The quick-clamping nut, is used for quick assembly and disassembly of the grinding disc without the use of additional tools (keys, screwdrivers, etc.).
It is designed for all angle grinders with M14 spindle thread, both small (115mm, 125mm, 150mm) and large (180mm, 230mm, 300mm), regardless of the manufacturer.
Just lock the grinder spindle with the lock, put on the washer, put the disc on the washer and screw it with the SDS-Clic nut without using a wrench.