The MB-436 kit is a complete MB-436 matte box system consisting the following products; MB-436 (0400-0436); 15 mm Swing away bracket for MB-216, MB-256 and MB-43X (0460-0600); 143 mm Flexible donut adapter ring for MB-435 / MB-436 & MB-455 (0420-0601).
This seamless clamp on gear ring clamps securely around the focus barrel of your lens by tightening one little screw (allen key is included). Once tightened, the slit in the ring disappears and makes the ring seamless. The tooth size is M0,8.