dc24v or ac230v optional push/pull force 250n 200mm/300mm/400mm standard strokes carbon steel chain is standard, stainless steel chain optional double link chain working more stably and smoothly sandblasted oxidative surface treatment simple but delicacy design, low noise operation silver, black and white 3 colors optional, other colors can be customized electronic overload cutoff with relax function endurance tests (30, 000 cycles) are carried out protection class ip32 flexible optional installation used in fire smoke removal, smart home, outdoor shaded, sun room, applied to awning window, sliding sash and casement window etc ce approved, 3 years guarantee