I make these out of paracord. The clasp is a carabiner I bend into shape by hand out of brass wire. Being made out of paracord, the straps themselves are extremely strong and durable, and the fact that I finish them by tying the ends into itself and melting the tips ensures it ought to never come unraveled. The carabiners are also very sturdy for the application. They definitely are not safe for climbing, but they handle the weight of my s-rt 101 (a heavy beast of a camera) with no issues or deforming.

Please note that since these are made by hand, there will be slight variations in the carabiners.