Smith & Wesson 990TA Neck Knife, Black Tanto, Whistle Sheath. The Smith & Wesson Whistle Neck Knife features a 3.5" 440C stainless steel tanto blade, powder coated black for non-reflective finish. Overall length measures 6.87". Weight is a mere 2.8 ounces, including the sheath and the breakaway neck chain. Plastic sheath has integral whistle which shrill sound is audible for over one mile. Great for the car, camping, hiking, walking and jogging! Specifications: Overall Length: 6.85" Blade Length: 3.5" Steel: 440C Teflon Coated Plastic sheath has integral whistle Handle: Zytel Coated 440C Weight: 3.3 oz.