The fourth element mask strap has been made using 100% recycled materials; The elasticated strap is made using rubber and recycled nylon; the clips are made from recycled waste ABS (Acrylonitrile butadiene styrene) plastic from the automotive industry.

The clips have been designed so that they will fit most mask buckles, and will fit all fourth element masks.

How to attach your snorkel to a fourth element mask strap
Once you have attached the strap to your mask, taking the second triglide clip on the strap, pull a small amount of the elastic strap through the buckle to create a little loop big enough to push your snorkel through and tighten to secure it in place.