Genuine Korky fill valve seal and cap for Korky fill valves 528, 582MP, 528T, and 528GT. MADE IN THE USA. Also fits Toto fill valve TSU99A.X, and TSU99A. To replace the cap turn off the water, then detach the refill tube. After that you will then snap off the cover on the top of the fill valve. Once the cap is off you will have to gently pinch the float arms inward and remove. Hold the valve, and twist about 1/8" counterclockwise. Once this is done you can replace the cap and reassemble it in reverse order.