Columbia River Knife & Tool Shrill, Fixed Blade Knife, 4.76, Resin Infused Fiber, Grey, Dual, Spear Point, Leather Sheath, G10 Handle/Grey 2075 The Shrill(TM) tactical boot knife knows its place on a mission: keeping you and others safe. It's no wonder this fixed blade has the name it does. With a dual-edged design it seems to pierce anything in sight.