For operation of rolling shutter of commercial and indusrial usage. Door weight up to 1000KGS. 1.Powerful starting strength 2.Overworking for a short time 3.Overheat protection 4.Limition seitch unit enables precise adjustment of door in up and down positions 5.Electric and manual operations 6.Release chain in case of power failure 7.Built-in control panel(KJ500C/KJ600C/JM500) 8.Control panel are available to infrared photocells, alarm lamp, and remote cintrol 9.Safety device for preventing the vehicle or people from damage in case of roller chain is break off