Black Widow Belt Buckle Knife. Be ready for Iron Man with this beautiful black widow belt buckle with hidden knife. A very handy tool always right where you need it. Always have a knife fast. 3" Magnetic Belt Buckle Knife. Buckle measures approximately 2 7/8" x 1 3/4". Stainless construction. Buckle holds removable 2 7/8" closed all stainless frame lock knife. Belt must be put on from right to left.