API 5CT K55 Casing Coupling Size: 4 1/2", 5 1/2", 6 5/8", 7", 7 5/8", 8 5/8", 9 5/8", 10 3/4", 13 3/8"Grade: J55, K55, N80, L80, P110Type: LTC, BTC, STCKeeping thousands of coupling stock with full size range, so our company can provide fast delivery. API 5CT K55 Casing Coupling