Item # bci1281296

The Kohler K-4421-U-0 has been discontinued

** See similar or replacement items below **

Kohler Cimarron 1.28 GPF Toilet Tank Only with Insuliner and AquaPiston Technology

Model: K-4421-U-0

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Product Overview

Product Features:

  • Tank only configuration - allows the opportunity to match pieces with a selected bowl
  • Covered under Kohler's 1 year limited warranty
  • Constructed of vitreous china for a clean and modern look
  • Insulated tank - prevents condensation from forming on the outside of the toilet tank and ending up on the floor 
  • WaterSense certified - toilet uses 20% less water than the current standard while still maintaining superior performance 

Product Technologies / Benefits:

  • AquaPiston: AquaPiston single flush canister technology uses the force of gravity and a precision-engineered tank, bowl, and trapway to create a strong, efficient siphon during flushing. The canister flush valve's 3:2 ratio optimizes flush performance and resists warping and deterioration, while its durable design features 90% less exposed seal material than a standard 3-inch flapper flush valve, guaranteeing leak-free performance. The light-touch canister requires lower activation force than a flapper, and once activated, allows water to flow into the bowl from all sides (360 degrees), increasing each flush's power and effectiveness.
  • Insuliner: An Insuliner tank liner reduces condensation on the outside of the toilet tank, ideal for high-humidity locations.
  • WaterSense Certified Product: To help make a difference on a global scale and to further its role as an industry leader in eco-performance practices, Kohler has established partnerships with a number of environmental organizations, including WaterSense. Many Kohler faucets are equipped with low-flow technology - they use less water, while continuing to meet superior performance standards.

Product Specifications:

  • Overall Height: 13-9/16" (measured from bottom to top of tank)
  • Overall Depth: 8" (measured from back to front of tank)
  • Overall Width: 17-5/8" (measured from rightmost to leftmost edge of tank)
  • Flow Rate: 1.28 GPF (gallons per flush)

This product is listed under the following manufacturer number(s):

*Denotes a finish or option that has been discontinued.

Manufacturer Resources

Dimensions and Measurements

8 in.
Flush Valve Size
3.25 in.
Gallons Per Flush
14.25 in.
Product Weight
33.50 lbs.
17.63 in.

Characteristics and Features

Tank Only
Design Features
Insulated Tank
Flush Type
Gravity Flush
Vitreous China
Trip Lever Placement
Water Efficient

Manufacturer Technology

Flush Technology

Warranty and Product Information

CA Drought Compliant
Country Of Origin
Made in America
Manufacturer Warranty
1 Year Limited
WaterSense Certified
Product Videos
  • Kohler AquaPiston technology provides the industry's best flush.
    Kohler AquaPiston Technology
    Kohler AquaPiston technology provides the industry's best flu...
Kohler AquaPiston Technology

Kohler AquaPiston Technology

Kohler AquaPiston technology provides the industry's best flush.