This 4-digit, programmable, down counting, timer kit makes use of a preprogrammed microcontroller. It has a 4-digit, 7-segment, red, 14mm LED display. It only displays seconds. After the START button has been pressed, it counts down from a starting value. The starting value can be set between 0 and 10 000 seconds (2.7 hours). It also has a STOP button. It has 4 operating modes that control the, active low, open collector, transistor output when the timer reaches 0: 1) Timer stops at 0 and the output is set active low. Reset to continue 2) Timer counts down to 0, sets output low, raps around to 9999 and counts down 3) When it reaches 0 the output is low for 20ms and the count is reset to initial value 4) Timer counts down to 0, sets output low for 20ms, raps around to 9999 and counts down. Reset to return to initial value Specifications: Supply Voltage: 9 - 12Vdc Supply Current: 50mA max. Output: transistor open collector 0.1A max. Dimensions: 52 x 67 x 12mm