A 30 millimeter plastic buckle from YKK. The male part has strap adjustment capabilities, while the female part is simple, and needs the strap to be either sewed to a loop or used with a tri-glide buckle. This buckle goes with everything, because green is the new black.
This buckle is made of polyacetal (POM), a thermoplastic used in precision parts requiring high stiffness, low friction, and excellent dimensional stability. POM works exceptionally well in wet and moist conditions. The YKK product code for this buckle is LB30R.