It doesn't fit very well:
https://cfmoto-forum.com/uforce-1000/air-filter-6366/

Sounds like you lost top end with this kit, but understand it's wasn't your goal.

https://www.elkasuspension.com/product/stage-1-front-rear-kit-for-cf-moto-u-force-1000-2019-to-2020/?c=72e1ba2726d6

I see what you mean. If they took a different pump I would say its just in it but the numbers are the same. From my experience all EFI systems must have a final filter between the pump and the injectors to ensure no particles or moisture get to the injectors. Even if it doesn't have anything other then what's in the tank before the pump, I would ensure is has one after...a large, steel bodied in-line one made by a trusted manufacturer.

EFI was introduced in 2-stroke snowmobiles back in the early 90's on the brand I ride in the winter months. Walbro is the fuel pump and tank supplier and do not run a fuel filter in their system. They do however run smart valves on the bottom of the tank before the pump. These have a fine mesh screen with a one way valve incorporated. If they detect water, they close. The neat part is, as you pull the rope to start the engine, it energizes the pump and pressurizes the system to the injectors. A battery is not needed for this system to run the engine. Sorry, a bit off topic, just wanted to point out that there isn't a fuel filter on this system. 

I have an ad blocker on my computer using Firefox and also on my Google phone using Chrome and have zero ads.

I sent them the original filter specs with pic's by email, no response. By phone he said they will make me an 11" filter, which they did but if they would have used my specs, 11" is the total length and they made me a 11" filter plus the neck, which is too long.

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In your case the 5X6 looks good.
I'm struggling loading pic's, slow process.

Another;

I returned the too short NU-8709ST and they sent me a revised NU+8710ST but this one is a bit too long and egg shapes the airbox, in turn the lid doesn't fit properly.

Got the new recommended unifilter (NU-8709ST) air filter recently, seems way too small. This in on my 2021 Uforce 1000.
Whats odd is, unifilter makes a full size option for this model as a cfmoto option is Australia but not in the states.
https://shop.cfmoto.com.au/0jya-111130-100-u1000-unifilter-air-cleaner

https://shop.cfmoto.com.au/5hy0-803000-u10-rear-cargo-cage

Someone help a guy out and measure the box L W H for me please... I want to order a bed storage box while I'm out camping so it's delivered when I get home! Much appreciated!

Measured from highest points, since the box is not smooth.
L 34 3/4"
W 54 1/2"
H 11 3/8"

Factory filter dimensions.