Package includes 2x 12.75inch long notches, 2x 6.9inch long notches, 1x clamp assembly head, 1x clamp assembly tail, 16x assembly screws (4x 3 / 8inch, 12x 1-1 / 4inch L), and assembly instructions; 1 set with 1 clamp; Wood required, not included More than lining up standard clamps and cauls; Attach notched to any length 1.5inchx1.75inch (3.2x4.4cm) board (equivalent to a 2x4 in half) with provided screws, set clamp and turn handle to tighten Make sure the 2x4s you use not twist; Drill holes for the outer-most screws when attaching the pressure pad Stock stay flat and prevents buckling of board because of the equally apply pressure from all four directions The 4-Way Pressure Release Clamp – Wood Panel Corner Clamping Woodworking Bracket Set handles stocking up to 6 inches (15.2cm) thick for simplifying the processes of countertops, furniture panel Build any length clamp with the with 12 notches for adjustability to handle a variety of stock widths; Turn the handle to tighten the clamp and unwinded the handle to release pressure; Clamp have pressure pad to damage of your stock, Manufacturer: Msioytog