Comparison : Item # C420B, 1/4 x 3/16 x 3/16 Inch (in) Reducing "Y" Connector
Item # C420S, 1/4 x 3/16 x 3/16 Inch (in) Reducing "Y" Connector
Item # C430B, 3/8 x 1/4 x 1/4 Inch (in) Reducing "Y" Connector
Item # C430S, 3/8 x 1/4 x 1/4 Inch (in) Reducing "Y" Connector
Item # C440B, 1/2 x 3/8 x 3/8 Inch (in) Reducing "Y" Connector