Every guy should at least own one survival knife. The SL Pro2 from Tool Logic ($37) packs a 3-inch, razor sharp 50/50 serrated blade, loud emergency signal whistle and a bright white LED flashlight, equipped with magnesium alloy fire starter, in a lightweight and compact construction. The rugged SL Pro2 is also built with a stainless steel frame with durable Zytel sleeve, pocket clip and lanyard hole.