This 3-piece set includes sizes 17mm, 19mm, and 21mm. Proxxon industrial hand tools are suitable for use in professional tyre change service centres and garages. These sockets are high alloy special steel for extreme wear resistance and can withstand up to 500Nm maximum torque. The plastic cover and plastic stop insert prevent damage to aluminium wheel rims and the surface of wheel nuts. They are 1/2" square drive and 130mm extra long for work in deeper rims. Supplied in a sturdy powder coated steel case.