A buckle includes a male coupler including a bar portion with an external surface, a first flange protruding from the external surface, the first flange being adapted for connection of a strap thereto; a female coupler with a hollow body having an opening therein, the opening including an end part at a first axial end of the hollow body and a slot part extending generally axially from the end part of the opening, the slot part having opposing lips extending along the slot, the hollow body having an internal surface complementary to the external surface of the bar portion; a detent for releasably holding the bar portion in the hollow body; and wherein the lips extend reentrantly and each lip is adjacent a respective inwardly-extending face in the bar portion.