CobraTec Knives Viper Hidden Release Folding Knife 3.125in D2 Black. 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. Specifications for CobraTec Knivess Viper Hidden Release 3.125in Automatic Folding Knives: Manufacturer: CobraTec Knives Blade Length: 3.125 in Overall Length: 7.37 in Blade Material: D2 Steel Knife Application: Folding Blade Handle Material: Titanium Blade Finish: Titanium Lock Type: Hidden Release Lock Sheath Material: No Sheath Weight: 4 lb Opening Method: OTF Closed Length: 4.25 in Fabric/Material: Aluminum Package Contents: CobraTec Knives Viper Hidden Release Folding Knife CobraTec Knives CTVIPERHRBLK: Viper Hidden Release Folding Knife 3.125in D2 Black