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. When installing it please watch the installation video by clicking the image. 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. Made of a special compound that lasts longer than the silicone and other knock offs. The flush valve requires a soft surface to make a seal but it also needs to be firm enough to support the weight of the flush valve.