Meets or exceeds UL 924, Emergency Lighting and Power Equipment CSA C.22.2 No. 141-15. Injection-molded, flame-retardant and high impact thermoplastic ABS housing. 100- 277V AC universal voltage operation. This twin head exit sign combo light is great for placing on doorways, school, restaurant, office building and warehouses. « The emergency exit sign lights built-in Ni-Cd AA 3.6V 1000mA backup battery provides minimum 90 minutes of emergency operation during a power outage and safe for charging. THREE mounting options for this exit sigh combo are available: end mount, hang mount and ceiling mount(canopy included). The led exit lights fits standard size junction boxes, suitable for indoor damp location- Universal (top or back) mounting. « This emergency signs luminaire can be used in a 100V-277V circuit for use at home, commercial and industrial lighting. It is suitable for apartments, churches, shopping malls, supermarkets, schools, hotel, restaurant etc.  Our LED emergency lights are offered high quality products at affordable prices backed by 5 year warranty and professional after-sales support