New, unopened product. Instant purchase OK. Shipped anonymously within 24 hours. These reliable and hassle-free instrument strap locks eliminate the need to remove or replace your guitar's existing strap buttons. Simply slide the installed Strap Blocks over your existing strap buttons to securely lock your strap in place. Strap Blocks are compatible with most OEM strap buttons and come in a convenient 4-pack. ・Strap Blocks, set of 4 ・Compatible with most OEM strap buttons ・No additional modification to the guitar required