Very good quality, good fit on another company's sup, just to fully inflate an 11-foot board it takes 40+ minutes with the car pump.

Must have if you have a SUP!!!!
At a gas station, you inflate it immediately. If you are at the beach, you give it up to 1 psi with the hand pump and then with the car pump from Lidl in 10 to 15 minutes it is ready at 12 psi..... Obviously, the car should always be running when the pump is working

At some point, the SUP inflates it.
I bought it with the idea that I would use it with the car pump and save time and effort.... Not even close.
With the hand pump, it's ready in almost 10 minutes, while with the car pump, it takes half an hour with breaks because it raises the temperature too much (both the pump and the adapter). It doesn't release as much air as the pump without it, which is why it heats up. I thought the one I got was defective, but it turns out that's just how it is. It's true that if you start with the hand pump, it's somewhat better, but what's the point....
Again, more effort, more time, a lot of noise, and you also strain the pump, which I don't know how safe it is!!
With a compressor or at a gas station where the pumps are much stronger, it might inflate much easier, but the point is to inflate it at the beach so you can easily transport it there!

Useful accessory!! I inflate my SUP with the "Michelin 12V Air Compressor" car pump. I agree with the previous review... Inflate it up to 3psi with the hand pump and then use the car pump... Saves a lot of time and effort!!