It uses a solid alloy valve body, which prevents rebound, does not hurt your hands, and saves effort. PTFE coating is also used. It can be used for trimming of wood, and it can be sharply and smoothly cut into clean, chip-free wood. This product is made of hard alloy. There are eleven sizes of the product to choose from. This product is suitable for wood cutting. Item Name: Grooving Router Bit Material: Hard Alloy Handle: 1/4 And 1/2 Size Details: 1/4 x 1/4: 2.2cm x 4.6cm(Approx.) 1/4 x 3/8: 2.2cm x 4.8cm(Approx.) 1/4 x 1/2: 3cm x 5.2cm(Approx.) 1/4 x 5/8: 3.3cm x 5.7cm(Approx.) 1/4 x 3/4: 3.5cm x 6.2cm(Approx.) 1/4 x 7/8: 4cm x 7cm(Approx.) 1/2 x 5/16: 2.4cm x 5.1cm(Approx.) 1/2 x 3/8: 2.7cm x 5.6cm(Approx.) 1/2 x 1/2: 3cm x 5.4cm(Approx.) 1/2 x 5/8: 3.2cm x 6cm(Approx.) 1/2 x 7/8: 3.8cm x 6.5cm(Approx.) Notes: Due to the light and screen setting difference, the item's color may be slightly different from the pictures. Please allow slight dimension difference due to different manual measurement. Package Includes: 1 x Router Bit