1. Use  PIC16f628a microcontrollers
2. Do not need batteries,Power from the  ignition
3. Standard FUTABA plug(Black-Negative Red-Positive and White-Signal)
4. Using high-brightness LED digital tube.
5. Input voltage range:3.5V-8.4V
6. Current consumption 25mA-60mA
7. Mini tachometer indicates up to 30000 rpm
8. Actual RPM= Display Digital *10
9. Body Size: 41mm L x 17mm W x 12mm H
10.Window Size: 30mm L x 15mm H
11.Weight:8.5g   (0.3OZ)