No longer being made. The company that made them is still around, but they didn't feel the market was big enough to continue mfg. of them. Would have to find a used one, or if you get lucky and find a new one one on a shelf somewhere.
I thought about getting one at one time, but it really isn't to bad for me. Since you have a regular vac. booster and not the Hydrabooster as I do, it is probably worse.