1, colour and lustre is gorgeous. 2, fine texture. 3, dry friction degree ... and conventional specifications will have + /-1 mm error, but the same batch ... 1/16"(2mm), 1/8"(3mm), 1/4"(6mm), 3/8"(9mm), 1/2"(13mm), 5/8"(15mm), 3/4"(19mm), 7/8"(22mm), 1"(25mm),1-1/4"(31mm), 1-1 ... /2"(38mm), 2"(50mm), 3 ...