This is a single strap used normally to hold a hard hatch cover closed in place by mission on some of their kayaks. Some hatches require a single strap and some require a pair of straps.
This complete strap is made up of 2 mounts, 2 lengths of 38mm (1 ½ inch) webbing strap (sewn into position on the elliptical mounts) joined by an adjustable length side release buckle, This makes one strap with a join in the middle. (This strap is available in 2 lengths- this is the 30cm length see below for the other length). These strap sets are normally used to hold down the hard hatch covers on kayaks that have a combination hard/ neoprene hatch closure system (e.g. Mission Eco Bezhig, Contour 490, Econizh etc.)