These air pump works great and are fun to experiment with. On the down side, they are a bit noisy (they will literally walk on your bench due to the vibrations) and their lifetime is between 200 and 500 hours according to the manufacturer datasheet. They suck air pretty fast and I have achieved a -700 mbar pressure with them which is a bit higher than what I expected from the datasheet. So, it's a good product but be aware of the lifetime and don't let them run when it's not necessary.