Construction screw for construction, bridge construction, and scaffolding bowl, buckle scaffolding used in conjunction. Play on the top, the role of the subiculum. Around a different name for the canonical name should be: adjustable base, adjustable backwater. The popular name: screw, building screw, oil Torr, U-shaped prop, screw on the Festival, screw the next section, prop stays, etc., welcome customers to buy.