Comparison : Item # CT-40, 1/4 Inch (in) Outer Diameter Manifold Tubing Coil
Item # CT-50, 5/16 Inch (in) Outer Diameter Manifold Tubing Coil
Item # CT-60, 3/8 Inch (in) Outer Diameter Manifold Tubing Coil
Item # BT-2M1, 1/4 Inch (in) Outer Diameter Tubing Recess Manifold Adapter Bushing Fitting
Item # BT-2M2, 5/16 Inch (in) Outer Diameter Tubing Recess Manifold Adapter Bushing Fitting