CobraTec Viper Hidden Release Automatic Knife Black. Introducing our new CobraTec Viper Hidden Release automatic. This knife doesn't open like most folders, but you'll know the secret to its smooth automatic action. The Viper Hidden Release utilizes a hidden bolster release; a simple, deliberate slide of the bolster from the front to back, deploys the blade and also unlocks it. You will soon determine that with its unique opening operation and svelte design, it is a capable EDC option and a part of your collection you'll be excited to show off. This blade is made of D2 steel and must be kept clean, dry and lubricated when not in use to offer you a lifetime of use. AnchorAll CobraTec OTF knives are backed by our LIFETIME WARRANTY. Black Titanium Coated D2 Blade 3.125 Inch Blade 4.25 Inch Aluminum Handle 7.375 Inches Overall Hidden Release Weight 4 Ounces