Comparison : Item # 11418, 1/4 x 1/8 Inch (in) Nominal Inside Diameter (ID) Reducing Street Coupling
Item # 11419, 3/8 x 1/8 Inch (in) Nominal Inside Diameter (ID) Reducing Street Coupling
Item # 11420, 3/8 x 1/4 Inch (in) Nominal Inside Diameter (ID) Reducing Street Coupling
Item # 11421, 1/2 x 1/8 Inch (in) Nominal Inside Diameter (ID) Reducing Street Coupling
Item # 11422, 1/2 x 1/4 Inch (in) Nominal Inside Diameter (ID) Reducing Street Coupling