The unique shape and size of the PP-1 is perfect for compressing the hydraulic piston by pushing the brake pads apart to speed service and pad replacementSlide the polished wedge shaped tool between pads to expand the gap and pre-set the pistons into the calliperUseful if you have accidently pulled the brake lever without your wheel and brake disc in the bikeReset the pistons without disassembling the calliper or removing the brake pads