This 4 x RT Motor Gear Set from Teradek includes 0.4, 0.5, 0.6-mod, and 0.8-mod wide drive gears for use with an RT MK3.1 or 3.0 lens control motor. Use this set to be prepared for almost any cine/ENG lens that comes your way during a shoot. Each gear is compatible with the focus, iris, and/or zoom rings on select cine and/or ENG lenses as listed below.