... 3.5 steel pipes, the top-cup, under-cup and button-cup. 2. Pole socket to connect to the same ... with a reliable self-locking function, It is safe and reliable, Carrying capability is strong, Efficient. 3. The ... ctructure of this scaffolding is uncomplicated, Easy to maintain and Convenient to management. 4. The cuplock Scaffolding is ... bridges, tunnels, land bridge , large-span scaffolding and so on.