These MD20B actuators require linkage kit LMD/AR-MBF Part No 914-1070-000 (RS < 795-9505') 795-9505 when used with MBF 3-port flanged rotary shoe valves. Schneider On/Off or 3 Point Damper Actuators MD20B-24V/-230V. Schneider MD20B Series 24V and 230V damper actuators for operating air control dampers in ventilation and air-conditioning systems for building services installations. For air control dampers up to approximately 4m² Torque: 20 Nm (180 in-lb) Nominal voltage: AC/DC 24V (< 795-9467') 795-9467 or 230V (< 795-9445') 795-9445 Control: On/Off or 3-point