Molded case only for indoor use . Can be made into double-sided clock. Using ac 220v 22v and 50hz 5hz, or 110v 11v and 60hz 6hz . With backup dc power supply, storage battery full charged going for more than 2 hours. Accuracy of travel time: day difference ¡ü 0.2s (in spring and autumn)£»day difference ¡ü 0.2s (in winter and summer). Working environment temperature: -40 to 50 ¡æ Installation: wall-mounted (only for one side), double suspenders, bilateral support, or according to customer requirements. Can be added the following functions£º Led spotlights luminous Timekeeping Adding rs485/422 serial communication function Adding rs232 serial communication function Built-in 485 repeater / splitter Gps time synchronization Long-wave timing signal synchronization Infrared mobile master clock synchronizes time Rf mobile master clock synchronizes time Infrared clock adjusted device adjusts time. Rf clock adjusted device adjusts time.Infrared mobile master clock synchronizes time and automatically records the synchronization time. Rf mobile master clock synchronizes time and automatically records the synchronization time. Diameter:300mm