pipe coupling grade:J55 K55 N80 C90 T95 P110. Thread type:NU EU STC LTC BTC. Size:2-3/8"-13-3/8" API 5CT pipe coupling Sizes range from 2 3/8" to 13-3/8".Steel grade including :K55, J55,L80,N80,C90,T95 and P110Thread types: NU, EU, STC, LTC and BTCQuality is fully guaranteed. Standard: API 5CT pipe coupling