3mm Uppercase Heartbreaker Signature Metal Letters Stamping Set by ImpressArt. ImpressArt Signature metal stamps are professional quality stamps, manufactured to the highest standard for durability and alignment. Stamps are engineered from hardened and sharp character edges ensure crisp, deep impressions project after project. Characters are marked on side of stamp for easy identification and orientation. This letter set comes in ImpressArt's patented storage case. Includes full uppercase alphabet and 7 bonus design stamps. Lightly coated with oil to prevent rust. Rated for stamping on Alkemé, aluminum, pewter, copper, brass, silver, gold, Stainless Steel 304-308, & other metals up to 66HRC Rockwell Hardness. Face ImpressArt logo toward you, when stamping; to ensure all of your design stamps come out right side up. Sold as one set.