Chromium-plated caps fitted to some wheel nuts are prone to swelling, making them incompatible with standard whole-size sockets. Half sizes allow the secure fitment for safe removal. Chrome molybdenum socket is hard-wearing, tempered and anodised for corrosion resistance. Durable thin-walled design for use with impact tools. 6-point socket is externally sleeved to prevent damage to alloy wheels and nuts. Socket sizes 18.5 and 19.5mm.