AT4B is an extremely versatile 24 Hour 365 Day Event Timers designed to support a wide range of applications. Such applications include: Home and Building Automation, Security, Access Control, Lighting Control, Etc. Input 12 to 24 VAC or VDC operation. Relay Standby current: 20mA with relays off combined with 40mA for each relay on. Four (4) Form "C" relay contacts are rated 10A @ 120VAC/28VDC. Each relay operates independently. Events/Programming Momentary and/or Latching Events. 254 individually programmed daily/weekly events. Block programming capacity can accommodate a total of 1778 events per week. 254 programmable Holiday dates. Features EE Prom memory protects against loss of programming due to power failure. Clock synchronization 60Hz (AC operation). Accurate crystal controlled clock (DC operation). "First man in" option. Standard or Daylight Savings Time settings. Automatic compensation for leap year. Battery Backup Built-in charger for 12VDC sealed lead acid or gel type batteries (Max. charge current 300mA). Lithium battery backup maintains clock. Order Altronix part # LB2032. Display Alphanumeric LCD display simplifies programming. Temperature Operating -20ºC to 49ºC (-4ºF to 120ºF). Storage -25ºC to 70ºC (-13ºF to 158ºF). Relative Humidity 85% +/- 5%.