OTC Professional Advance Timing Light allows accurate adjustment of base and advance timing reading. Its unique features include an adjustable knob that measures centrifugal, vacuum and computer advance and an on/off touch control. The other features include all metal inductive pickup, reflected super bright Xenon flash, removable leads with positive twist lock connector, one touch control, durable plated ABS housing with over-molded grips, heat-resistant over molding on battery clips, and blow-molded case.