This is a trap for bathroom floor sewage of buildings. With existing products, builders had to buy sewage traps of various heights depending on height of building concrete. With this product, they can instantly adjust sewage traps according to height of concrete of construction sites improving convenience in construction or inventory management. 

7⅞"×7⅞"stainless steel plates can be used if (blue ring) is added (in this case, just 315/16" is available)