Probably the Drimaster 3 upholstery tool. I hope its an improvement over the 1 and 2. I spent $400 on the first edition which almost immediately snagged fabric with the metal lips while pushing the tool forward. For $60, they sent me an updated head with somewhat improve metal lips. The only reason I stick with it is because I have so much $ in it. I'm too proud and cheap to make the switch right now.