Improved design for easier measurement of brake rotors. Depth rod for measuring pad wear. Pointed anvils and 3.50" longs arms to inspect rotors before turning or replacing them. Improved anvil and arm design to better get into scores and tight spaces. Easy to read digital display with inch/metric conversion 0-4.00"/0-100mm range with .001"/.01mm graduations. Uses an SR44/357 battery.