Features:
*Use PIC 16F628a microcontrollers
*Small Vokume, Convenient to Carry
*Do not need batteries, power from itself
*Standard FUTABA plug (Black-Negative, Red-Positive, and white- Singal)
*Use 4 digital tube to monitor the engine`s speed
*Mini tachometer indicates up to 30,000rpm (actual RPM = Display digits x 10)
*Increased self test feature

Specification:
Working Voltage: 3V - 12V
Working Current: 25mA - 60mA
Weight: 15g
Size: 54mmL x 20mmW x 15mmH