OTC 3365 Professional Advance Timing Light 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