... location limit protect 2.Max lifting force is 800kg 3.rolling speed is 4rpm SMD800/SMD600/SMD300 series chain-device roller ... 800kg, Power supply Ac230v, absorbed power from 180w to 500w. Rolling speed 4rpm, double location limit protect.Technical Character:Lifting force300kg ... :style 1:DM 04style 2:ST 04style 3:HT 04 Rolling shutter motor