FIRSTINFO Auto Metal Sheet Plate Butt Joint Weld Soldering Clamp Auto metal sheet plate butt welding clamps with high quality construction; 4 pcs in one set. Holds panels edge to edge with almost no gap which allows full penetration of the weld. Patented level adjustment allows accurate joining of dissimilar thickness of materials. Level adjustment allows flat alignment of top or bottom surface of panels. Level adjusts between 0 and 3mm either side.