One, I have one. It works well but I am going to be going with another can that accommodate both evacuation under boost and vacuum. The new install is much cleaner with the factory connections, but my install didn't work like the video. I drilled the hole in the same spot and I spun the fan with my fingers and it hit the nut and bolt. I had to mount it sort of cocked to the passanger side a few inches due to the fan and it hitting a sensor- the video truck has a intake on it, I don't.
Be aware the can is a bitch to empty, dorman part 61105 would make emptying it much easier.
Just attach a hose to the fitting and be able to drain it remotely.
Pm me if you'd like to buy my can that has been installed for 1,000 miles, paid $145 shipped.