This is Knobbles and Bobbles' beautiful glass melon knob with antique coloured fittings, the diameter of this knob is 4cm and the bolt will fit through a door that is up to 2.5cm thick.
Longer bolts available to buy for this design of knob, from the website menu. Please go to All knobs -> Fittings and Longer Bolts.
Each knob is supplied with the glass head and metal fixings including bolts and a washer. Any questions? Please email firstname.lastname@example.org.