1.Name: tubing couplings 2.Std Ref: API 5CT 3.Grade: J55,K55,N80, ... "EUE141.30*158.756.051. Name: tubing couplings2. Std Ref: API 5CT3.API couplings for oil tubing and casing.4. Grade:J55,K55,N80 ... ,L80,C90,P110,N80-1,N80-Q5. Size:tubing coupling from ... case ,wooden pallet or by customer requests API 5CT EUE tubing couplings