Wilson Chart Drives PROGRAMMABLE (24HR.-48HR.-4DAY-7DAY-8DAY-16DAY-31DAY-32DAY) DEPENDABLE DURACELL BATTERY OPERATED COST EFFECTIVE!!!!! also available in 2hr -NO WIRES SCREWS OR REPAIRS-REPLACEABLE MOVEMENT-SNAP OUT OLD MOVEMENT SNAP IN NEW ONE IN SECONDS---SAVE ON DOWN TIME..................... -TEMP RANGE:     -40 F TO +170F / PLASTIC CASE NOT EFFECTED BY SULPHUR GAS,HEAT,COLD OR SALT ATMOSPHERE DEPENDABLE ELECTRONIC QUARTZ MOVEMENT /EXCELLENT PERFORMANCE IN TIMEKEEPING