We use the Exouds heatsinks on all UcD400 builds. It is designed to mate with this adaptor plate. These parts make mounting your UcD modules a simple easy affair.
With the counter sunk holes you can easily mount five UcD modules in minutes rather than taking hours to try and line-up all the mounting holes with your chassis.
Do it right the first time and assure that you get proper heatsinking for your UcD amplifier build.