SmallRig AB stopskit4302 aredesigned for the automatic lens calibration of DSLR and mirrorless camera lenseswith MagicFIZ Wireless Follow FocusSystem(ID:3781,3782); The AB stops are exquisitely compact and can be freely positioned for mounting on the seamless focus gear rings (3291,3292,3293,3294,3295,3296) via a reverse clasp, or easily removed. 1. Free positioning of the AB stops for easy automatic lens calibration.2. Reverse clasp design for easy installation.3. Can be used as a universal accessoryforseamless focus gear rings.Note: When installing the AB stops, please press the hook under the seamless focus fear ring in place.Compatible With1: Compatible with standard M0.8 module, 13.2mm wide seamless focus gear rings2: Compatibility: 3291、3292, 3293, 3294, 3295, 3296A/B Stops x 8Product Dimensions: 17.4 x 6.0 x 8.54 mmPackage Dimensions: 135.0 x 110.0 x 10 mmProduct Weight: 4.0 ± 5.0gPackage Weight: 12.5 ± 5.0gMaterial(s): ABS+PC