Round glass knob. Comes with a 2-1/2" long nickel plated, smooth head bolt and nut. Depression Green color. 1-1/8" diameter, 1-1/8" projection. Note: This glass knob is durable. However, please bear in mind that it is made of glass, and that glass knobs and handles require special care during installation. No power tools - use only hand tools to install glass hardware. To tighten, turn only the nut on the back end of the screw (this is one reason why the screw head is smooth and has no slot). Do not turn the knob itself as it may cause breakage. Tighten with care and do not over-tighten. Remember: this is glass.