Designed as an add-on and available in five styles; Bird, Clover, Diamond, Oval and Star. Simply layer the Aged Brass backplate underneath the knob, twisting the screw to secure. DimensionsDiamond: 50mm (w) x 70mm (h) The Diamond Backplate is paired here with our 18mm Aged Brass Knobs. Hole diameter: 4mm. Suitable for an M4 screw, and compatible with all styles in our Knobs collection.