This is Knobbles and Bobbles' unusual wooden round knobs with turquoise accents that reminded me of lightning hence the name. The knob measures 40mm diameter. The bolt will fit through a door that is up to 2.5cm thick. Each knob is supplied with the knob itself and metal fixings including bolts and washers. Any questions? Please email email@example.com or ring us on 07746 357625.