High Compatibility: 3mm, Length: 39mm. A valuable addition to any woodworking tool. 10pcs High Speed Steel Router Bits: 10 different types of the most commonly used router bits, including straight, V-groove, cove, slot cutter and more. A great engraving set to meet your different needs. 10pcs: 10 different in one set, each one is shaped to fit different angles or situations, suitable for engraving, chamfering, grooving, boring, hollowing. High Quality: 10 different shapes and 10 different types of the most commonly used router bits. To fit different woodworking situations, meets most of your needs for deburring, edge grooving, carving, milling, engraving, drilling. Made of high-speed steel for exceptionally precise cuts, good wear and heat resistance. Widely used: Suitable for detailed work, such as sanding furniture, model trains, buildings and airplanes. On a wide range of materials including: wood, ABS, acrylic, PVC, plastics, etc.