
Kohler GP83064
Score: 82/100
Kohler GP1078441
Score: 85/100Rankings

The Kohler GP1078441 is a genuine OEM replacement flapper designed specifically for Kohler two-piece toilets featuring Class Five flushing technology. Its key strength is the precise 3.25-inch rubber seal that effectively prevents phantom flushes and maintains high-efficiency performance. However, it is incompatible with non-Kohler models and may degrade faster in hard water environments.

The Kohler GP83064 is a 2-inch red rubber flapper designed as a genuine OEM replacement part for select older Kohler one-piece toilets. It features corrosion and chemical resistance to chloramines and chlorine tank cleaners, ensuring durability in harsh environments. The product includes a stainless steel chain and hook for lever connection, offering an exact fit for specific vintage models without the need for adjustment.
| Attribute | ![]() | ![]() |
|---|---|---|
2 inches | 3.25 inchesbest | |
1 countbest | 1 countbest |
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| Attribute | ![]() | ![]() |
|---|---|---|
Material & Durability(2) | ||
Material | TPR/Rubber | Rubber |
Seal Type | Clip-on | Rubber |
Design & Features(2) | ||
Chain Material | Stainless Steel | Standard |
Installation Type | Clip-on | Direct Replacement |
Packaging & Support(1) | ||
Warranty Period | 1 year | 1 Year Limited |
Compatibility & Fit(5) | ||
Flush Valve Compatibility | null | Kohler Class Five |
Flapper Diameter (inches) | 2 inches | 3.25 inches |
Toilet Type Compatibility | One-piece | Two-Piece |
GPF Compatibility | null | 1.28 |
Flush Valve Size | 2 | 3.25 inch |


Products in the top-left offer the best value (high score, low price).

Search results lack dedicated professional reviews from major outlets like Wirecutter or Consumer Reports. Retailer listings emphasize the product's genuine OEM status, exact fit for listed models, and resistance to corrosion and chemicals, positioning it as a direct fix for aging toilets.
Limited user reviews are available, with feedback praising the product as a simple, problem-free replacement. Common praise centers on easy installation and restored function in compatible toilets, with one user noting the flush valve simply turned into place and the flapper clipped on with no problems.

Plumbing experts and editors from sites like Ferguson and CPE Supply highly recommend this part as the definitive OEM replacement for Class Five systems. They highlight its precise 3.25-inch seal as critical for preventing phantom flushes and its durable rubber construction for resisting corrosion.
Everyday consumers generally report high satisfaction, with many noting that the flapper perfectly fits their Kohler models and restores the toilet to like-new flushing performance. Common praise includes the ease of installation and the elimination of running toilet noises.
“Replaces original flapper and flush valve that always gave us problems. Flush valve simply turned into place... flapper simply clips onto it... no problems at all.”

“Perfect fit for my Kohler Cimarron-flush like new!”

“No more running toilet; lasted 2 years in hard water”


