Check the listing for details. 4" x 4 Digit Wireless Synchronized Clock, IP Based, Automatic DST Reset. Condition: New. Listed at 189.00 USD. FeaturesTime is automatically set by Simple Network Time Protocol(SNTP)- no master clock or serial connection required.Supports Wi-Fi- no need of network cable distribution.Static IP or DHCP addressing12 or 24 hour display Automatic Daylight Saving Time change (if applicable)Adjustable brightness (brilliant, bright, normal, dim, off)Capability to receive realtime countdown commandIf connection to NTP server is lost the clocks will continue to run on the built-in time base. When the connection is restored it will synchronize automatically.The clock features time loss notification by having a light on on the right lower cornerOptional FunctionsBuilt-in bell relay. We can add a built-in bell relay to the clock, then it can be connected to a bell and the bell can be programmed to ring at 30 different moments using the management software.Temperature and humidity display. We can add a temperature sensor or humiture sensor to the clock, then it can display time, temperature and/ or humiture altenately.Purchase Links of Optional FunctionsBuilt-in bell relay: Optional Built-in Bell Relay Upgrades for GlobalTime NTP Clocks | eBayTemperature sensor: Optional Humidity and Temperature Sensor Upgrades for GlobalTime NTP Clocks | eBayHumiture sensor: Optional Humidity and Temperature Sensor Upgrades for GlobalTime NTP Clocks | eBay Notes (1) The management software only supports Windows system, doesn't support Mac.(2) We will send you the data sheet and manual by email. Please check your email after placing orders.(3) On the backside of the clocks, there are two holes for hanging them on the wall, and we will include nails into the packages so mounting kits are not necessary. However if you need them, please specify the type you need when placing orders, or we won't include them in the packages.