For use with 4 1/2" (115mm) angle grinders and sanders when removing rust, grinding of welds, parting lines on casting and carbon steels or removing rough edges on most surfaces. 40 and 80 grit flap disc in stock. The High grain adhesion is for a long life which outlasts conventional sanding discs, with these flap discs there is no backing disc required, it fits directly onto an angle grinder and with different grits of discs you'll be able to finish your job a lot quicker than any conventional method. Goggles should always be worn when using this tool. The flap discs are available 5, 10 or 20 packs. Features: -Size: 4 1/2" (115mm). -Aluminium Oxide backing pad. -lasts up to 25 times longer than a regular sanding disc. -40 grit