These incredible value studs from Torridon help to give you traction on the most challenging of surfaces. Ideal for all rubber and Vibram type soles in boots, wellies or shoes. Thread diameter 4.2 mmSpanner/socket size to fit studs 7 mmHead height 4 mmScrew shaft length 9.5 mm.Flanged hexagon head self tapping studsBright zinc platedManufactured to DIN 6928 C