Professional advance timing Light allows accurate adjustment of base and advance timing reading Unique features include an adjustable knob that measures centrifugal vacuum and computer advance and an on/off touch control Includes all metal inductive pickup and reflected super bright Xenon flash Durable plated ABS housing with over-molded grips Easy to install no set up required and connects easily into the vehicle's OBD II connector and is able to display status in 15 seconds