Buckle and respirators having such buckles. The buckle has a movable cinch bar allowing a strap to be inserted into and be secured by the buckle by opening the cinch bar and inserting the strap. The cinch bar then returns to a closed position and supports the strap over the cinch bar. The cinch bar may be deformable through the use of a living hinge connecting the cinch bar to the body of the buckle. The cinch bar may be split into two members, each being deformably coupled to the buckle body, perhaps with living hinges.