The Gralab 555 Electronic Digital Timer has a "touch-type" dust and moisture resistant keypad that protects it in darkroom/lab conditions.
Digital timing circuits cycle off a quartz crystal time base with little reaction to power line interference and none to frequency variations.
This model has extensive timing capacity ranging from a tenth of a second timing up to 59 minutes, 59.9 seconds with automatic reset; repeat a cycle over and over by pushing a single button.
Half-inch high, red LED's display minutes, seconds and tenths. Adjust brightness from "high" to "off". independently of the timed switch.
Compact and lightweight, The Gralab 555 at 2.25 x 4.5 x 9.25", can be positioned at a 20-25 degree angle on its own stand, sit on rubber pads which provide traction on flat surfaces, or wall mounted using keyhole slots on its underside.
This models feature a permanent plastic boot over the power and outlet control switches to prevent contamination or corrosion.