
Korky 100BP
Score: 90/100
Fluidmaster Glacier Bay Flapper
Score: 85/100Rankings

The Korky 100BP Ultra High Performance Flapper is a universal 2-inch toilet flapper designed to maximize flush performance while conserving water across various gallon-per-flush ratings. Constructed from exclusive chlorine-resistant red rubber, it offers superior durability in harsh water conditions and features adjustable settings for precise water optimization. It is best suited for homeowners with standard 2-inch toilets in areas with chlorinated, hard, or well water.

The Fluidmaster 5401GBP4 is a durable 3-inch adjustable silicone flapper designed primarily for Glacier Bay and similar high-efficiency toilets. Its main limitation is its lack of universal fit, making it less suitable for non-compatible brands. It is best suited for owners of Glacier Bay toilets seeking a long-lasting upgrade with water-saving adjustability.
| Attribute | ![]() | ![]() |
|---|---|---|
2 inches | 3 inchesbest | |
1 countbest | 1 countbest |
Click an attribute name to sort · Green = best, red = worst (relative to this comparison)
| Attribute | ![]() | ![]() |
|---|---|---|
Material & Durability(2) | ||
Material | Rubber | Rubber/Silicone |
Seal Type | Sealing Ball | Silicone |
Design & Features(3) | ||
Chain Material | Stainless Steel | Unknown |
Installation Type | DIY | Direct Replacement |
Flapper Type | Adjustable Flapper | Adjustable |
Packaging & Support(2) | ||
Warranty Period | 5 Years | 10 years |
Certifications | TAA/BAA | |
Compatibility & Fit(6) | ||
Flush Valve Compatibility | 2-inch | 3 inches |
Universal Fit | true | false |
Flapper Diameter (inches) | 2 inches | 3 inches |
Toilet Type Compatibility | Standard | Post-1994 HET |
GPF Compatibility | 1.28-5 | 1.28-1.6 GPF |
Flush Valve Size | 2 | 3 inches |

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

Professional reviewers and plumbing experts, including those from Clorox, highly endorse the Korky 100BP as the longest-lasting flapper available. Editors at supply sites praise its high performance and precise water control, noting that it significantly outperforms generic brands in chlorine resistance tests. The product is highlighted for its universal design, making it ideal for contractors who need a single solution for various toilet brands, with no performance drop across different flush volumes.
Everyday consumers rave about the product's longevity, with many reporting it lasted up to seven years in harsh water conditions. Users frequently praise the ease of installation, noting it takes only five minutes without tools. Common themes include strong flush performance despite water savings and perfect fits for brands like Kohler. Recurring complaints focus on the chain being too long and occasional initial seal issues that require adjustment.

“lasted 7 years in hard well water”

“5 minutes, no tools”

“saves hundreds of gallons yearly”




Search results lack dedicated expert reviews from major review sites like Wirecutter or Consumer Reports. Retailer and manufacturer pages emphasize reliability, corrosion resistance, and water-saving capabilities, positioning the product as a high-quality upgrade specifically for Glacier Bay toilets.
Consumer feedback from Home Depot reviews is consistently positive, praising the ease of installation and the product's effectiveness in stopping leaks and fixing running toilets.