It does not work with the Huawei electric pump that is capable of inflating car tires.. it may work with another pump

I wasn't sure because of the reviews I saw, but I contacted the store and confirmed that it is exactly what it says, a valve adapter! It fit perfectly and seems to be of very good quality too!

I start by saying that this is an adapter and not a pump, compressor, or air compressor. The adapter does not produce/release air...!!! Any reasonable person can understand that with a manual pump it will take over an hour to inflate a SUP, so with the adapter and an air compressor, this time will be reduced to 4 to 8 minutes. Now, if you try to inflate a SUP with a compressor that is meant for balls, using the 12 volts that go into the car's cigarette lighter socket, then it will indeed take you more time and maybe it won't be able to fully inflate it. It's like trying to inflate a car tire to 28psi or 32psi with this compressor... well, it will never inflate. So, for the job that this adapter is designed for - and its job is simply to convert the SUP valve to the car valve that has a common air gauge - it is perfect!!!

I bought it with the purpose of inflating the SUP using a portable pump (for cars, bicycles, balls). Unfortunately, the airflow is very small and I gave up, I don't even know how long it takes to fill. It will definitely inflate faster at a gas station, but I would recommend using an electronic air compressor that allows you to adjust the pressure and stops automatically.

Useless,
I thought I would inflate the sup with an air compressor.
Of course, with a small portable air compressor, it takes 2 days to inflate, from a gas station it takes about 12 minutes, if they don't curse at you in the meantime.
But this is dangerous when you don't need to exceed 15psi, a pressure that is too low for large car air compressors, whose gauge is unclear at such low pressure.