This is a classic GraLab 300 processing timer, a mainstay of darkroom technology for decades.
The GraLab 300 uses large motorized hands and luminous digits to be visible from a distance. It can be configured to turn an enlarger or other device on or off for a precise time. It's silent and utterly reliable.
Its mechanism provides extreme accuracy for long time intervals: +/-.015% at its maximum dial setting.
It features two outlets, traditionally for an enlarger and a safelight. It has a configurable buzzer to indicate the end of its timing cycle - helpful if you use it to time negative processing.
It's way more intuitive than a digital timer, and substantially cooler.
Expertly manufactured by Dimco-Gray in Centerville, Ohio, this device can be expected to outlive whoever owns it. It carries UL and CSA electrical certification.
It has a heavy three-wire grounded power cord and key-hole slots in the back of its case to allow it to be wall-mounted.
This timer has been lightly used, and is in like new condition. It comes with its original instruction booklet.