Acroprint Optional Backup Battery for Model ATT310 Electronic Totalizing Time Recorder ES900 Electronic Payroll Recorder/Time Stamp/Numbering Machine, Backup Battery, Ribbon Cartridge Multifunctional machine features battery backup to ensure the perpertual calendar maintains the correct time. Identifies early or late punches with the I-Mark (*) to make auditing time cards easier. Over 300 selectable print formats. 1- to 8-digit consecutive numbering, 13 selectable preset messages or custom messaging in seven languages. Left- or right-hand margin printing. Uses standard time cards. Password protected. Manufacturer's one-year warranty. 4-1/2w x 9-3/4d x 7-5/8h. Shpg. wt. 6 lbs. Backup Battery For use with Time Recorder Model ES900 (ACPES900), sold separately.