Hexagonal glass knob. The bolt is inserted from the front through the head of the knob. A perennial favorite since the late 19th century on furniture of all kinds and in the kitchen, bathroom and every other where in the home. Comes with a 2-1/2" long smooth-headed nickel-plated bolt and nut, just as in the old days. 1-1/4" diameter, white. 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.