A lens holder attached on an Arm, "D Holder Extension Bar" or "Grip Base DIII w/ Rubber Grip D" etc. to carry 28LD series/LD series attachment lens. Compatible product is sandwiched between Lens Holder [screw] and Lens Holder Base of this product. In combination with "AD-LD Mount Converter for UCL-165AD"/"M67-LD Mount Converter for UCL-330/165M67", other series attachment lens can be attached as well in addition to 28LD series/LD series lens. Weight : 44g (1.6oz) [air] / approx.14g (0.5oz) [underwater] Compatible arm/base : Arm SS/S/M/L YS Arm MS/M Grip Base D4 D Holder Extension Bar Grip Base M1 D Holder Extension Bar D Holder D Holder Extension Bar Grip Base DIII w/ Rubber Grip D Grip Base DII w/ Rubber Grip D