Features:
2 1/16 inch diameter, only 1 1/2 inch deep
Microprocessor controlled
1-2-4-6-8-10-12 cylinder selection
Automatic night-dimming
RPM Range to 9900 (four LED Digits--the two on the right only read 0s)
Push button to program switch
RPM activated switch function:  Choose from Normally Open (turn on an accessory at the desired RPM) or Normally Closed (turn off an accessory at the desired RPM)
High RPM recall