I took the pads out of course. It's only usable if the pistons are 2-3mm inwards at most. If you let your pads wear out completely and then need to reset the pistons, that tool is completely useless. Not to mention if you squeezed levers without pads or a bleed block accidentally/to clean pistons. So unless you replace your pads every other week and only need to reset a tiny bit, just get the plastic levers that actually work