HotStamps can be attached to any Walnut Hollow hot tool by screwing on and off with pliers after tool has cooled. Use to personalize any project with a variety of 24 individual metal number and symbols. Hot Stamp on wood, paper, leather, fabric, and more. This Number Set includes Numbers 0-9, Asterisk, Pound, Exclamation, Question, Ampersand, Music Note, Ribbon, Star, Heart, "S" Brand, Comma, Circle, Square, and Tree shapes. Number height is 5/8".