I have for sale a vintage SOG Government Recon S21 fixed blade knife. It was made by Seki of Japan for SOG. It uses SK-5 Carbon steel with an HRC of 57-58. These knives were made for an unnamed governmental agency, The more common variety uses Stainless steel. This uses the better carbon steel. The sheath is nylon. This knife is pre-owned but not used. It is in excellent condition.