The M4 SeberTool if highly collectable and was the first keychain plier-tool to have both locking blades AND all-outside-opening blades. It retains the keychain attachment mechanism of its M2 and M3 predecessors.Blades and Tools As stated above, all the blades are outside-opening, and all blades lock open. There are three blades in each handle:knife blade, with double edge V grind. 1-1/2" long (35mm) medium Phillips screwdriver medium flathead screwdriver two-sided file blade. Single cut and double cut serrations combination eyeglass screwdriver/bottle opener tweezers Locking Mechanism Blades lock open via a backspring tab that engages a notch in the blade. Lock release is accomplished by pressing down on a small tab. (see photo)Other Features The M4 is able to quickly attach or release from a key ring, by means of a hole on the opposite side of the plier jaws. Securely closed up, the tool is quite unlikely to accidentally release from a key ring or lanyard loop.Sheath None.Dimensions Folded length = 2" (52mm) Unfolded length = 3-3/4" (97mm) Thickness = 3/8" (10mm) Weight = 1.7 oz (46g) stainless versionSeberTech Tools were sold with "M4 SEBERTOOL USA" cast into the plier pivotShop with confidence.