These blades will cut urethane cleanly from inside the vehicle and are thinner than most blades on the market. All Equalizer® TimeSaver™ Blades are made of hardened, stainless steel and can be easily resharpened dozens of times. Because of the leverage put on the bearings and the yoke bar, we do not recommend using these blades in a standard oscillating tool, only the Equalizer® TimeSaver™ tool. Because these blades can cause regular oscillating tools to be damaged, we have color-coded them to match the tool. If the tool is not yellow then do not use the blades in the tool. Made in USA.