Total length: 175 mm Expansion Tube length: 75 mm, diameter: 12 mm Support Rod length: 100 mm, diameter: 10 mm The Plank Support Bracket can support and fix various wall shelves, such as bookshelves, display stands, garage storage racks, decorative shelves, bathroom shelves, shoe shelving, and more. It is suitable for a variety of DIY wall mounting applications. Installation Steps: 1. Measure the hole spacing and drill a hole in the wall; the hole depth should be less than 75 mm. 2. Insert the bracket support pin into the wall hole along with the expansion plug and black screw cap. 3. Tighten the support rod clockwise until the expansion plug expands fully within the wall. 4. Drill a corresponding hole of the correct size on the side of the board, matching the wall hole spacing. 5. Insert the board onto the plank support rods. Important Tips: 1. Use an 11 mm drill bit for drilling holes in the wall and a 10 mm drill bit for drilling holes in wood. 2. Place the silver metal ring on one end of the expansion tube before inserting it into the wall. 3. Each board must use at least 2 concealed brackets, installed at the same horizontal level. (Each pair can support up to 11 lb / 5 kg.) Note: Test the hole diameter on a scrap piece of wood to achieve the desired fit. Material: Plastic + Metal Color: Brown Package Contents: 8 x Concealed Floating Shelf Brackets Note: Lighting and monitor settings may cause slight variations in color between the image and the actual item. Measurement may vary by ±1-3 cm.