... .. Items are ISO,A,AG,G,W,UN,NPT,ACME,API et Threaded insert SIZE RANGES ARE 11ER/16ER/22ER11IR/16IR/22IR ... universal use(threading insert). LDC shows yellow coating,suitable for processing steel.16 ER 19 W LDA16 IR 18 NPT LDC16 ER ... quality ,low price .We can satisfiy all customers' requirements Threaded insert( ISO,A,AG,G,W,UN,NPT,ACME,API )