OTC's No. 6596 Brake Pad Gauge allows for a definitive measurement of brake pads to determine remaining life. The unique design allows for measurement on the vehicle without the removal of any components in most cases (wheel assembly or brake caliper). This handy tool provides quick, easy verification of brake pad condition via a color code scale - Red means No, Green means Go! Crafted with rugged materials to ensure long term performance and durability. Calibration procedure: when probe tip is in locked position (resting on either body ledge), barrel measurement should be 4mm - adjust set screw and end screw as necessary to achieve 4mm measurement. Value is at the core of the OTC tool and equipment portfolio. For a simple repair or the most complex drivability concern, these award-winning tools universally solve problems faster, and at better value, than any other product line available. Whether it’s a specialty tool or unique piece of service equipment, OTC provides top solutions to modern automotive service challenges while increasing technicians’ productivity and shop profits.