The most reliable and hassle-free instrument strap lock system ever devised No need to remove or replace existing strap buttons on your guitar just slip easily installed Strap Blocks over the existing strap buttons and that's it-you're ready to go, with your strap locked securely in place Strap Blocks work with most OEM strap buttons Available in convenient four-packs containing one black pair and one red pair Fender Strap Blocks will stop your strap from slipping off your axe and potentially causing serious damage. It's happened to all of us. You're playing guitar, lost in the groove, and next thing you know your guitar strap is slipping off and sends your guitar crashing to the floor. It's embarrassing and it can hurt your guitar. Fender Strap Blocks help stop this from happening. These rubber end pieces quickly slip on the strap peg after your strap is on. It stops the strap from slipping off. Strap Blocks are easy to use, no drilling or modification to your guitar needed. You get two pairs of blocks in each package. Protect your guitar from strap failure with Fender Strap Blocks.