British Sil-Nylon Small Insertion Sack. New. Olive Green.
Genuine issue 'waterproof' bag designed as a liner for the side pouch of the military ruck sack. Totally watertight fabric (the HH is off the scale!) but no seam-sealing so ingress through seams if submerged. Closure is via a basic tie and toggle. Could also be used as a stash bag for kit, footwear etc. Recommended.