Amazon.com: Fender Guitar Strap Lock with Chrome Buttons and Wood Mounting Screws, 1 Set of 2 Security Guitar Strap Locks for Guitar and Guitar Strap, Black and White Felt Washers, 1 Set :
Amazon.co.jp: Guitar Strap Button, Guitar Strap Lock Button Metal End Pin - 2 Mushroom Style Strap Lock Buttons for Acoustic Guitar, Electric Guitar, Bass or Ukulele Ffxs : Musical Instruments