We've covered the First Tactical Diamondback previously here at Shooting Illustrated, and the Viper is another folding tactical knife in the same product line. While the Diamondback is larger and features a tanto-style blade, the Viper is more "pocket-friendly" and has a spear-point blade.
Single-hand opening is easily achieved thanks to the unique "thumb bridge" mechanism that allows quick release of the blade using either hand. The beefy pocket clip is reversible for left- or right-handed users and the liner lock us oversize for easy manipulation. At 4.2 ounces, the Viper is lighter than the Diamondback, and with a 2.5-inch blade, certainly more friendly to less-permissive environments for pocket-carry.
Whether you're looking for an EDC folding knife, a sturdy companion for opening letters and boxes or simply a rugged knife that won't set you back much, the Viper is worth investigation.