Pat numbers on blade 2170537 and 2037943 And other side of blade it reads Hammer Brand with the arm and hammer. This is a small knife which is in good used old condition, It is very solid for such a small knife. Also has a metal loop at the other end. The knife is 2 inches closed and 3 1/2 open. Knife only has one blade,with some type of pearlish handle which is in good shape. Thanks and please see pics. Most of the items we sell are used and/or vintage. Please ask all questions before bidding, and look at our pictures. All sales are final, and your satisfaction is paramount, if you have certain requirements, as with serious collectors, please ask questions before bidding. We are not experts in all fields and will answer any item specific questions you may have about what you are looking for in an item. Thank you.