Optical system uses low radiation laser beam to indicate toe-in or toe-out. Single leg configuration and reversible contact probes allow on-ramp use. Works on most cars and light commercials with rim diameters from 200mm(8") to 600mm(23.5"). Powered by 2 x AA batteries (not included) and includes operating instructions. Features & Benefits:Optical system uses low radiation laser beam to indicate toe-in or toe-out.Single leg configuration and reversible contact probes allow on-ramp use.Works on most cars and light commercials with rim diameters from Ø200mm(8") to Ø600mm(23.5").Powered by 2 x AA batteries and includes operating instructions.Model No. GA50 Specifications: Model No GA50 Brand: Sealey Nett Weight: 14.93kg Wheel Rim Capacities: 8" - 24" Rim Diameter Measuring Range: +/- 2deg Laser Beam Height: Under 50mm Laser: Class II, 1.0 Milliwat, Wavelength 620-680nm Battery: 2 x type AA 1.4 Volts Estimated Battery Life: 6-12 Months, Dependent on Use Switch: Momentary O