The World SR Dual is a two-way adjustable buckle; you don't have to sew the female side to anything, and you can tighten either side.

The buckles are specified to American webbing widths. For the 40 mm / 1.5" buckles, the inside width is 39.5 mm (with clearance) because 1.5" is actually 38.1 mm. This means a full-width 40 mm webbing needs a bit of help to pass through but it works without violence.

Made from Delrin; a high-quality polymer which is both shock absorbant and very resistant to extreme temperatures.

Made by ITW Nexus

These are high-quality stuff, tough enough for military etc. rough use and abuse!