Features: 1.These letter stamps are suitable for permanent marking of metal, plastic, leather and wooden items. 2.Use a basic hammer to permanently engrave names, addresses, and other emotions on all different types of media including jewelry. 3.This stamp and content are made of high-quality alloy structural steel, which is resistant to wear and is guaranteed to be durable. 4.The structure of this letter stamp can withstand almost any punching work you throw at them. 5.Each stamp is safely organized in a portable box, and the sturdy plastic upper open box is also easy to store. specification:Item Type: Letter Stamp Set : 1 Set (36pcs) Main Material: 40CRV (Alloy Structural Steel) (Note: The product is composed of complex materials) Purpose: Leather stamp Size: Diameter of The Stamp Head: Approx. 3mm / 0.1in (manual measurement, with small errors) PackageList:36 xLeather Stamp 1 x Storage Box NoteThe letter stamps are composed of complex materials.