1.: This toilet flapper is made of high-quality soft rubber, which seals reliably to prevent water leakage and help you save money on water bills in the long run. 2. Perfect Fit: This flapper toilet replacement is designed for 3-inch flush valves and meets US and Canadian plumbing standards. Its size ensures that the toilet tank flapper stays open long enough to ensure a thorough flush. 3. Efficient Design: A flapper toilet solution designed specifically for Gerber Toilet Flap 99-788, which can effectively replace worn or leaking flappers, restore normal toilet function and reduce water waste. It is an ideal choice for maintaining the performance of Gerber flapper systems. 4.: Replacing a toilet tank flapper is simple and no tools are required. Just turn off the water, drain the tank, remove the old flapper, and then install the flapper toilet using the included chain. If the old flapper is difficult to remove, cut carefully to avoid damaging the valve. 5. Affordable Solution: This package contains 4 Gerber toilet flapper replacements, providing you with spare parts for future use. Avoid costly plumbing repairs and prevent future leaks by installing a Gerber toilet flapper yourself. 6. IMPORTANT: Always check your toilet tank for a 3 opening. This Gerber flapper measures 4.9' x 3.66' and is designed for 3 flush valves.