ACU-TECH™ HDPE Drainage Cap & Lining ( Nut & Tail ) HDPE Drainage Cap & Lining Range of Sizes Available.50mm ( 40mm BSP 1 ½" ) 50mm ( 40mm BSP 1 ½" ) Brass Lining50mm ( 50mm BSP 2" )63mm ( 50mm BSP 2" )ACU-TECH™ HDPE Drainage Cap & Lining ( Nut & Tail ) BSP ThreadSize in mm / BSP Thread Size*Select