The diopter stage can be used at the back of a 4 inch x 5.65 inch clip-on a matte box, or independently with a rear-mounted clamp adapter. Diopters up to +3 can be fitted, and the position of split diopters can be adjusted with an integrated friction wheel. As with the diopter frame, a safety device and ¼” mounting threads are included. Compatible with LMB 4x5, LMB-25, LMB-15 and LMB-5.