The Z Adapter II is an optional product to add INON Arm II compatible ball-joint on a strobe, light holder or base. An arm product is combined in combination with a clamp. Metal body enhances stability of combined arm. It is useful when handling long arm via this accessory as the Z Adapter II attached on the Grip Base D4/M1 will have its ball-joint vertically or horizontally. Effective length: 59mm (2.3in) Weight: 58g (2.0oz) [air] / approx.36g (1.3oz) [underwater] Compatible arm/base etc. Grip Base D4, Grip Base M1, D Holder, D Holder Extension Bar, Port Arm for MRS, Port Arm for UFL-MR130 EFS60, Tripod Adapter Compatible strobe etc. Z-330, D-200, S-2000, Z-240, D-2000, D-2000S, D-2000W/Wn, D-180, D-180S, Z-220F, Z-220F, Z-220S Double Light Holder LE, Quad Light Holder LE, Strobe Light Holder LE, Strobe Light Holder LF