The universal Jack provides a method pf adjustment which can be used at either the top or bottom of a scaffold support structure. It can be supplied with welded base plate or U type Stirrup Head. U-Head is to hold timber beams securely in place. Adjustable U-Head offers 500mm of rolled threaded tube that can be adjusted by a double handle nut. Dia Sizes: 343638 mm Thread: 4 TPI Acme (Form) Lengths: 100150200375450 mm Base Plate: 150 x 150 x 6 mm Nut: Malleable Cast Iron Nut