This is a Gerber TAC II Military Survival Knife with the locking sheath. The blade is double edged and double serrated. Blade is .149" thick and 1.139" in depth. Blackie Collins is the designer. The handles on TAC IIs are molded Zytel, full-hidden-tang. Comes with original locking sheath. Serial #A08861. Has some sheath scratches on the blade, otherwise excellent condition.