Fluidmaster 501P21 2-Inch Universal Longer Lasting Chlorine Resistant Solid Frame Toilet Flapper Fixes common running toilet and ghost flushing problems Easy-to-Install , universal fit for most 2 flush valves Solid frame prevents twisting for a secure seal Chlorine and hard water resistant materials Kink free chain included Microban prevents growth of harmful microbes Fits pre-1994 toilets