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. Double-ended 6-point socket is externally sleeved to prevent damage to alloy wheels and nuts. Socket sizes 18.5 x 19.5, 19 x 21, 21 x 21.5, 22 x 22.5mm with a 75mm 1/2"Sq Drive Extension.