Made of impact resistant plastic. With side by side, T and side by side joints, it is very suitable for drilling and repairing wood joints in woodworking. Quick Positioning - The quick stud clamp can be self-centered on the board for quick and precise positioning and connection. Adjustable Position - The position of the baffle can be adjusted as needed. The adjustment range is 0 to 50 mm, suitable for 6/8/10 mm drills. The thickness can be used for cards with a thickness not exceeding 31 mm and cards with a thickness not exceeding 1-1 / 4 ". Widely used for drilling wood, used for most manual woodworking drills and electric drills. Specifications: Material: plastic + metal Color: yellow, blue, green, black (optional) Use: Wood drills Brush: 6/8 / 10mm Perforation size: 200 x 72 x 86 mm How to use: 1. Adjust the positioning scale to determine the distance between the first block and second block and the edge of the board. 2. After fixing the position, select the drill bit corresponding to the drill guide to start drilling. 3. After drilling three holes, remove the nuts from the scale. 4. Use the locating pin to secure the hole on the third hole (make sure the distance between each hole is the same). 5. Drill all straight holes.