Rhea, because the basic principle of the scaffold is by the German LAYHER invention (real) company, also known as the industry was "rhea frame". Mainly used for large-scale concert light frame and background frame. 
Alias: wheel rack, roulette scaffolding. 
Basic principle, the use of cast steel or stamping wheel welding on the column, bar through the wheel on the rail head and the column connection, fixed by pin chip. (need) using inclined reinforcement bar with large 
Features: installation, convenient disassembly, pin after fixed only need to use a hammer or a wooden hammer to tap on a fixed can. 
Accessories not easily lost, pin spacing with rivet on the rail, not lost. 
Good stability, widely used in bridge casting support, construction, stage background, lighting and other fields