1 time use (1 and done) and put down a catch basin. I put this on a 12\" brake disc that was stuck. Sprayed with rust dissolver and PB Blaster, hammered to try and break it free BEFORE using the puller. It started leaking after just a few pumps. The 15 ton relief valve leased pressure, no way it could have been close to 15 tons. Finally popped free, but the hydraulic fluid was empty before I could pull the second disc. I was able to refill it through the hole where the pin from the handle goes in a table spoon of liquid at a time, fill the hole, insert plunger, press, repeat, until the ram started to move, then added another ounce. I used DOT4 because that's what I had. I figured I couldn't break it anymore than it was already, and it worked . For $80 I saved $100's that a shop would have charged, but it took 5 hours of my time. If your time isn't worth anything, go for it.
Vevor Hydraulic Gear Puller 
