This page will explain with images how to size your LeMans.
The LeMans comes in many sizes. While it may look complicated it's actually very easy to determine which model will fit in your cabinet. One of the first things you're going to want figure out is the "swing" of your LeMans. Refer to the chart below to pick the swing that you need.
First decide which type you want. There is a left and a right version.
Next you need to measure the opening of your cabinet. Make sure you measure the opening of the door, and be mindful of any hinges you may have in the opening. Use the sizing chart below to pick your size.
16 1/8" to 17 3/4"" Small
17 3/4" TO 21 1/4"" Medium
21 1/4" TO 25" Large
The LeMans II can be installed in a full height door cabinet, or under a drawer as long as you have the minimum height of 21 1/2" inches in your face frame opening.
The last thing you need to check is that you have the proper internal clearance in your cabinet box. If you've already determined that a LeMans can fit in your opening, you just need to make sure that you have a minimum of 32 1/4" in the INSIDE of the cabinet and 19 3/4" depth. Again, this is inside dimensions of the cabinet, not the box itself.