The D'Addario patented Planet Lock system fits virtually any guitar and stays locked in place until you release the side pin. Unlike ordinary strap lock systems, the Planet Lock is designed to fit securely on your guitar's existing end pins, eliminating the need to change the hardware on your guitar. Plus, you can use the same strap on different guitars. The Planet Lock is safe, secure, and easy to use. They are adjustable from 35" to 59.5" long.