1.material:high carbon chrome steel 2..diameter:2.381mm-25.4mm 3.certificate:ISO9001:2008 4.G100 G200 ... .080601/16”~1”1.501.503.000.0951001/16”~1”2.502.505.000.01252001/16”~1”5.005.0010.000 ... ”~1”1-10,…..,-1,0,+1,…..,+9281/16”~1”2.00-12,…..,-2,0,+2,…..,+12401/16”~1”4.00-16,…..,-4,0 ... further Information,Plz contact us! G1000 G500 G200 G100 1/2" 12.7MM carbon steel ball