You may have heard about the patented RigidCore
Through an informative new website, UWS reveals the science behind this feature and how it works to give UWS boxes unrivaled strength and integrity. In short, the process fills the extra-thick aluminum lid with a hardening foam, which prevents the warping and bending common to other toolbox brands. As the site shows, RigidCore
See the results for yourself at www.uwsta.com/rigidcore.