The Smith & Wesson Viper gravity knife is awesome. Simply pull down the sliding button on the handle's right side and flick the knife open. The blade flips out vertically and lock securely into place. Just slide the button down and you can flick it closed just as easily. The handle is black coated aluminum handle. The bead blast stainless blade is partially serrated. The slide release button (double as safety) and the Viper has a removable pocket clip.
Specifications:
Overall: 8"
Blade: 3.5"
Weight: 3.2 oz.