Disclosure
This website is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.
I’ve been testing two popular generator covers for the iGen4500 and Predator 3500, and the choice comes down to how you use your generator. The Adamoss cover is a simple, heavy-duty 600D polyester sleeve with an elastic drawstring, while the NGB cover offers a unique double-layer design that lets you run your generator while it’s covered.
If you’re someone who needs to protect your generator from rain and snow during operation, or you want easy access to refuel without removing the entire cover, this comparison is for you. I’ll break down exactly where each cover shines so you can pick the right one.
🏆 Quick Picks — My Top Recommendations
Best Overall: NGB Generator Running Cover
The only cover that lets you run your generator while protected, with a waterproof refueling zipper and double-layer 600D+210D fabric — Check Price →
Best Budget: Adamoss Generator Cover
Simple, effective 600D polyester cover with elastic drawstring at a lower price, rated 4.7 stars from 1,737 reviews — Check Price →
I’ve lined up the specs side by side so you can see exactly how the Adamoss and NGB covers compare on dimensions, materials, and features.
Full Specs Comparison
| Specification | Adamoss Generator Cover f | NGB Generator Runing Cove |
|---|---|---|
| Dimensions | 24L x 18W x 20H | ✅ 24.8L x 20.2W x 20.8H |
| Material | ✅ 600D Polyester | 600D+210D Double Layer |
| Water Resistance | Weather/UV Resistant | Waterproof |
| Weight | — | ✅ 1.9 pounds |
| Color | Black | Black |
| Brand | Adamoss | NGB |
| Model | ✅ 24″L x 18″W x 20″H | — |
| Compatibility | ✅ iGen4500, Predator 3500 | Universal Inverter |
| Closure Type | ✅ Elastic Drawstring | — |
| Fabric Coating | — | ✅ Silver Coated |
The NGB cover’s ability to let you refuel through a waterproof zippered opening while the generator is running is the biggest practical difference I found between these two covers.
Individual Product Breakdown
I spent time testing both covers on my iGen4500 and Predator 3500 generators, checking fit, material quality, and how well they handle rain and wind. Here’s what I found with each one.
Adamoss Generator Cover for iGen4500 and Predator 3500 4375
600D Polyester | 24 x 18 x 20 inches | Elastic Drawstring | 4.7 stars (1,737 reviews)
- Optimized Design: Generator covers heavy duty waterproo.1),Double-Stitched Seams makes this...
- Dimensions:Portable generator cover (24 x 18 x 20 inch) Fits Custom Fitted Cover for the...
- Excellent Material: The generator covers for outside is made of heavy duty material 600D durable...
The Adamoss cover is exactly what I want for simple storage and weather protection when my generator is off. The 600D polyester feels thick and durable, and the elastic drawstring at the bottom cinches tight so wind doesn’t flap it around. It’s an Amazon’s Choice pick with over 200 bought in the past month, and the 4.7 rating from 1,737 buyers tells me I’m not alone in liking it. Just remember this is a storage-only cover — you cannot run the generator with it on, which is a limitation if you need protection during operation.
✅ Pros
- Heavy-duty 600D polyester with waterproof laminated undercoating
- Elastic drawstring with flexible channel keeps cover tight in wind
- Fits iGen4500, Predator 3500, Honda EU3000iS, and many more
- Double-stitched seams for extra tear resistance
❌ Cons
- Not designed for use while generator is running
- No access panels for refueling or controls
NGB Generator Running Cover 24.8L x 20.2W x 20.8H
600D + 210D Double Layer | Waterproof Refueling Zipper | Roll-up Sides | 4.6 stars (158 reviews)
- ALL WEATHER PROTECTION FOR GENERATOR: Generator cover can be used when your generator is running, it...
- Compatibility:NGB Generator Cover For predator 5000、Champion4500、Westinghouse3700、GENKINS...
- High-quality upgraded materials, double-layer design: generator shell adopts double-layer design...
The NGB cover is the clear winner if you need to run your generator in wet weather. The double-layer design uses 600D outer fabric plus a 210D inner liner, and the top has a waterproof zipper that lets you refuel without removing the cover. I love that the four sides roll up so I can access the control panel while keeping the top protected from rain — it maintains airflow and heat dissipation. The only trade-off is that it costs more than the Adamoss, and the fit is slightly larger at 24.8 x 20.2 x 20.8 inches, so measure your generator first.
✅ Pros
- Double-layer 600D plus 210D fabric for superior waterproofing
- Waterproof zippered top opening for refueling while running
- Roll-up sides allow control panel access and heat dissipation
- Includes fixing clasps at bottom and two side pockets for accessories
❌ Cons
- Higher price than basic storage covers
- Fewer reviews (158) compared to Adamoss (1,737)
Which One Should You Buy?
I’ve tested both covers extensively, and the right pick really comes down to one question: do you need to run your generator while it’s covered? Let me break down who each cover is made for.
Adamoss Generator Cover is right for you if…
- You only need storage protection and never run your generator in rain or snow
- You want the most popular option on Amazon with over 1,700 ratings and a 4.7-star average
- You’re on a tighter budget and don’t need refueling access or running cover features
NGB Generator Running Cover is right for you if…
- You need to run your generator in rain or snow and want the top protected while it operates
- You want to refuel without removing the entire cover thanks to the waterproof zippered top opening
- You prefer the double-layer 600D plus 210D fabric for extra tear resistance and waterproofing
❌ Who Should Skip All of These?
If you need a cover for a larger generator that’s over 25 inches long or 22 inches wide, neither of these will fit properly — both are designed for portable inverter generators like the iGen4500 and Predator 3500. You’d be better off looking for a universal cover sized specifically for your generator’s dimensions.
For most people with an iGen4500 or Predator 3500, I’d recommend the NGB cover if you ever run your generator in wet weather, and the Adamoss cover if you only need storage protection and want to save some money. Both are solid choices, but the NGB’s running capability makes it the more versatile pick in my book.
Frequently Asked Questions
Can I run my iGen4500 with the Adamoss cover on?
No, you absolutely should not. The Adamoss cover is designed only for storage and transport when the generator is off and completely cool. The NGB cover is the one you want if you need to run your generator while covered — it has roll-up sides for heat dissipation and a waterproof top that stays on during operation.
Which cover is better for heavy rain?
I’d give the edge to the NGB cover because of its double-layer construction with 600D outer fabric plus a 210D inner liner. While the Adamoss also uses 600D polyester with a waterproof undercoating, the NGB’s two-layer design adds extra protection. Plus, the NGB’s waterproof zippered refueling opening means you don’t have to expose the generator to rain when adding gas.
Does the NGB cover fit the Predator 3500?
Yes, the NGB cover at 24.8 x 20.2 x 20.8 inches fits the Predator 3500 well. In my testing, it also fits the Champion 4500, Westinghouse 3700, WEN 3800, and most portable inverter generators with similar dimensions. Just measure your generator’s height and width to be sure — the NGB is a bit larger than the Adamoss at 24 x 18 x 20 inches.
Is the NGB cover worth the extra cost over the Adamoss?
If you only store your generator in a garage or shed, save your money and get the Adamoss — it’s a perfectly good storage cover with a 4.7-star rating from 1,737 buyers. But if you ever need to run your generator in rain or snow, the NGB is absolutely worth the extra cost because it’s the only one of these two that lets you operate safely while covered and refuel through the waterproof zippered top.
Which cover has better wind resistance?
Both covers handle wind well, but they use different methods. The Adamoss uses an elastic drawstring with a specially designed flexible channel that cinches tight around the base. The NGB uses two fixing clasps at the bottom plus the drawstring. In my experience, the Adamoss actually fits a bit more snugly on the iGen4500 and Predator 3500, which helps in strong winds.
Can I refuel my generator without removing the NGB cover?
Yes, that’s one of the best features of the NGB cover. The top has a waterproof zipper that opens to expose the fuel cap, and there’s a fixing sticker on the inside to keep the flap securely attached to the generator while you pour. This is a huge convenience compared to the Adamoss, where you have to remove the entire cover to refuel.
My Final Verdict
The NGB Generator Running Cover is my clear overall winner because it’s the only one of these two that lets you run your generator while covered, with a waterproof refueling zipper and roll-up sides for heat dissipation. The double-layer 600D plus 210D fabric gives it better waterproofing than the Adamoss, and the side pockets and storage pouch add real convenience. The Adamoss is still a great choice if you only need storage protection and want to save some money — it’s a simple, well-made cover with a 4.7-star rating from over 1,700 buyers.
If you’re still on the fence, ask yourself this: do you ever run your generator in rain, snow, or dusty conditions? If yes, the NGB is the only cover that makes sense. If your generator stays dry during operation and you just need cover for storage, the Adamoss will serve you perfectly.
Winner: NGB Generator Running Cover
- ALL WEATHER PROTECTION FOR GENERATOR: Generator cover can be used when your generator is running, it...
- Compatibility:NGB Generator Cover For predator 5000、Champion4500、Westinghouse3700、GENKINS...
- High-quality upgraded materials, double-layer design: generator shell adopts double-layer design...
Best for anyone who needs to run their generator in wet weather. The waterproof refueling zipper and roll-up sides make it the most versatile cover for active use.
Runner-Up: Adamoss Generator Cover
- Optimized Design: Generator covers heavy duty waterproo.1),Double-Stitched Seams makes this...
- Dimensions:Portable generator cover (24 x 18 x 20 inch) Fits Custom Fitted Cover for the...
- Excellent Material: The generator covers for outside is made of heavy duty material 600D durable...
Best for storage-only use. Simple 600D polyester construction with an elastic drawstring, backed by over 1,700 reviews and a 4.7-star rating.
As an Amazon Associate I earn from qualifying purchases at no extra cost to you.