... :Dia.25mm, Dia.30mm, Dia.35mm, Dia.40mm, Dia.60mm Metal base:Zinc alloy and galvanized A Dia.4mm hole on the ... furniture accessories, fresh feeling for our life! We also supply metal base for the knob, also screwed nail! There is a dia ... . 4mm hole in the bottome of the metal base! Please kindly see the pictures! We try our best to ...