A headband for protective head gear is provided at opposite ends with overlapping members formed of a stiffer material than the band itself. These extension members are made adjustable longitudinally with respect to one another by means of a tensioning arrangement and a lug is provided on each member which allows tension to be applied to the headband by the fingers of one hand of the wearer of the head gear. A lever associated with the tensioning means is actuated with one finger to release the head-clamping pressure of the band.