Comparison : Item # SS-6-HRCGT-4RT, Hex Reducing Coupling (ISO Tapered Thread)
Item # SS-8-HRCGT-4RT, Hex Reducing Coupling (ISO Tapered Thread)
Item # SS-8-HRCGT-6RT, Hex Reducing Coupling (ISO Tapered Thread)
Item # B-6-HRCGT-4RT, Hex Reducing Coupling (ISO Tapered Thread)
Item # B-8-HRCGT-4RT, Hex Reducing Coupling (ISO Tapered Thread)