DiMarzio's ClipLock Quick Release Guitar Straps are made from the same heavy duty nylon used in car seatbelt. Unlike polypropylene, nylon has a smooth, satin feel, allowing the guitar to slide freely during performance. The fabric conforms to your body and adds a new level of comfort, yet it is strong enough to hold even the heaviest of guitars. The Cliplock system allows you to change guitars quickly on stage and is the most secure fastening method around. These straps are the industry standard for strength, comfort and security.