brown fused alumina FEPA P grit, for making premium quality jumbo roll,sanding belt stable quality ... 2090 Knoop scale, 9.0 Mohs scaleMagnetic Material 0.0076% Grit Size Available (P):12, 16, 20, 24, 30, 36, 40 ... ,brown aluminium oxide,fused alumina brown fused alumina FEPA P grit