Check the listing for details. Waverly Guitar Strap Button, Ivoroid Button, Gold Screw. Condition: New. Listed at 17.52 USD. Details make the difference: these beautiful strap buttons match our bridge pins, and the knobs on Waverly guitar tuning machines. They'll add a touch of class to your guitar. Each is precisely machined (none of the unsightly mold lines found on plastic buttons), and polished to accent the beauty of the material. A special countersunk brass bushing helps protect the button against overtightening — a unique StewMac feature. Button diameter: 17/32" (13.28mm) Button height: 7/16" (11.11mm) Our ivoroid strap buttons are made of Galalith, a dense and durable casein-based material that polishes beautifully. Popular in the early 20th century, Galalith is seen today mainly in collectible vintage jewelry. It cannot be molded; each pin is precisely machined and has none of the unsightly mold lines common to plastic