... external threading insert SIZE :11ER/16ER/22ER 11IR/16IR/22IR etc.. Items are ISO,A,AG,G,W,UN,NPT,ACME,API ... carbide internal & external threading insert SIZE RANGES ARE 11ER/16ER/22ER11IR/ ... Items are ISO,A,AG,G,W,UN,NPT,ACME,API et1.tolerance below +0.01mm~-0.01mm 2.Apply ... products.WENLING LIFENG PRECISION TOOL CO.,LTD!!! carbide internal & external threading insert