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, box and papers. Serial #A03765. Excellent condition.