6Pcs Hidden Flying Shelf Brackets Hidden Invisible Heavy Duty Shelf Bracket Wall Shelf Bracket 10mm x 100mmOOTDTYComs: These flying shelf brackets are made of cold-rolled steel and plastic, high hardness and durability. Easy to install, strong and stable. The hidden design is more beautiful and space-saving. The product is widely used in the decoration industry. How to use it:1. Punch holes in the wall. Hole diameter: 12mm; Hole Depth: 73mm-75mm; The stroke of the hole depends on the length of the board.2. Insert the end of the expansion pipe into the wall, and rotate the hexagonal handle tightly to open the expansion to hold the wall firmly.3. According to the pitch of the hole on the wall, punch holes on the board (thickness ≧ 15mm). Hole diameter: 10mm; Hole Depth: 100mm.4. Attach the board to the wall. (If the expansion does not open, hold the expansion and rotate the handle,The expansion will be concave, make it convex with your fingers, rotate the handle firmly,The expansion will open, hold the situation for 20 seconds,Loosen the expansion and go to the second step.)Specification:Material: Iron + PlasticColor: BrownSize: Phi; 10mm x 145mm/Phi; 0.39" x 5.71"Quantity: 6pcs. Note: Size for manual measurement, there may be 0 to 1mm error, belongs to the normal phenomenon. Due to the difference between different monitors, the picture may not reflect the actual color of the item. Package Included: 6pcs x Shelf Holders