Hibbent Large Toilet Flapper for Gerber 99-788 3 Inch
- Material: Rubber
- Item Weight: 0.26 pounds
- Color: Blue
- Size: 3 Inches
Last refreshed Sep 8, 2026 · Based on the Amazon listing and published specifications, not hands-on testing.
A straightforward 3-inch flapper for Gerber 99-788 style tanks. Confirm your valve opening measures 3 inches before ordering.
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ASIN: B08V5CXV1CModel: 1pCategory: Toilet Flappers
Overview
Hibbent's 3-inch flapper replaces worn or leaking flappers on toilets with a 3-inch flush valve opening, including Gerber 99-788 models. It measures 4.9 by 3.66 inches and uses a rubber seal with a stainless steel chain and hook.
This is sized for the less common 3-inch flush valve opening rather than the standard 2-inch size most toilets use, so measuring the valve first matters more than the brand name on the box. It is aimed squarely at stopping a running or leaking tank, not at cosmetic upgrades.
- Fits 3-inch flush valve openings
- 4.9 x 3.66 in rubber flapper
- Stainless steel chain and hook
- Tool-free installation
Who it's for
Homeowners with a Gerber 99-788 or other 3-inch flush valve toilet dealing with a running or leaking tank. It is not a fit for the more common 2-inch flapper toilets.
Pros and cons
- Sized to match the Gerber 99-788 valve directly
- Stainless steel chain resists rust
- No tools needed for installation
- Only fits 3-inch valves, not the more common 2-inch size
- Single color and size option
Performance notes
The rubber flapper seats over the 3-inch flush valve opening to form the seal that holds water in the tank between flushes, with a stainless steel chain and hook connecting it to the flush lever. The 4.9 by 3.66 inch size is built to the same opening spec as the Gerber 99-788 valve.
Specifications
| Brand | Hibbent |
|---|---|
| Model | 1p |
| Dimensions & fit | |
| Item Weight | 0.26 pounds |
| Size | 3 Inches |
| Product Dimensions | 1 × 2 × 3 inches |
| Construction & materials | |
| Material | Rubber |
| Color | Blue |
| Other details | |
| Style | Compatible With 3-inch Gerber 99 788 |
| Item Model Number | 1p |
| Part Number | NARF5_09135 |
Frequently asked questions
Does the Hibbent flapper fit a Gerber 99-788 toilet?
Yes, it is sized to match the Gerber 99-788's 3-inch flush valve opening.
Will this fit a standard 2-inch flapper opening?
No, this flapper is sized for 3-inch openings only, so measure your valve before ordering.
What is the chain made of?
A stainless steel chain and hook, designed to resist rust over time.