Easy dredge Pissing / Easy dredge Pissing

, I design this one that is easy to dredge . Its main design principle is that where is under main sewer is opende a rounded hole. when it is not used, it can be beautiful and isolated bad smell well through putting a loved rubber . If it was jammed, we could put the seal ring out and dredge it by some simple tools. what's more , we needn't destroy its strcutures to take them out . We only return the seal ring after finishing ourselves.