About the D'Addario 50mm Quick Release Acoustic Guitar Strap, Black:
 
The D'Addario Quick Release guitar strap allows the player to easily disengage from the guitar. Just squeeze the quick-release and you're free: no knots to struggle with and no need to drill a second strap button into your guitar. It won't come loose during play, and the extra length of the cord keeps the guitar strap from interfering with your hand when playing near the headstock. Each nylon woven strap comes with our easy-sliding shoulder pad that is as comfortable as it is functional. Adjustable length from 35 inches to 59.5 inches long.