Fender Strap Blocks (4-Pack) Black/Surf Green - Fender strap blocks are the most reliable and hassle-free instrument lock system ever devised. No need to remove or replace existing buttons on your guitar; just slip easilyinstalled Strap Blocks over that’s it—you’reready to go, with locked securely in place. work withmost OEM available convenient four-packs.•All Black•2 Black / 2 Daphne Blue•2 Surf Green•Set of four Blocks•Compatible buttons•No guitar modifications required accessories, Fretted Instrument accessories & Parts, Fretted Instrument accessories, Straps & Strap Locks, Strap Locks