I cannot find a size on this but as it won't fit me at 34 waist I would think s/m and dates back to a time when I was 30 waist . There is a bit of damage inside and the webbing has stiffened with age . Has a little zipper pocket and I just checked zip works! Whistle inside pocket at moment , not original though as I am pretty sure just a sensible addition. Original spreader bar with gaastra sails imprint. Leg straps clip in and out , spreader bar adjusts both sides so you can keep central.