Quantity 10 Mansfield Genuine 630-0030 Flush Valve Seal. The Red Seal Is The Only Seal To Fit The Tower Flush Valve. The Mansfield 006300030 210/211 Flush Valve Seal UPC: 046587000088. This seal is flat. After being used it may develop a ridge or cone shape. It is the most common cause of the toilet leaking and being hard to flush. The package says for 210 and 211 it is referring to the flush valve model number not the tank number so it is also the seal for the 160 because the 160 uses the 211 flush valve.