These Microtech sheaths are made from heavy duty nylon cordura, velcro and have heavy duty stitching all around. To release your knife from the sheath you pinch the sides of the clip release. The size in height is adjustable via the clip for about an inch up or down and the sides also expand to fit a variety of knife widths. This custom built knife sheath also attaches to the belt or web gear with an adjustable trifold velcro loop so it can be added or subtracted without opening the belt up. Additionally this loop can be opened to attach via a wide velcro strip to other tactical gear.