Tresham Toilet Repair Parts - K3981
By Kohler

Q. "How do I find my Kohler model number?"
A. For our customers' convenience, we often list both the model number and the tank number of the Kohler toilets we offer parts for. If you already know your model number, that's great - but oftentimes this information won't be available to you. What you'll need to do then is look for the TANK number, which is right where you'd expect it to be on the inside of your toilet tank. Grab a flashlight, carefully remove your tank lid, place your lid somewhere safe, and look around inside your toilet tank for a 4-digit number beginning with either a 3 or a 4. Certain specialty toilets may have a 5-digit number starting with a 1. The number will be either molded into the porcelain or stamped on in blue or black ink. This is your tank number and you can use it to find the parts you need to fix your toilet.

Q. "There are letters and/or numbers after the model number inside my Kohler toilet tank - what do those mean?"
A. Kohler offers many variations of almost all their toilet models, and has experimented in the past with many different features. Typically, numbers (or a single letter/number combination like K4 or Y2) after the 4- or 5-digit model number indicate the color code for your toilet. If your model number is followed by letters, those usually have different meanings to indicate the features of your toilet or will indicate that you have a specialty Artist Edition toilet.