UWS Blue Series-Single Lid Box: The Single Lid Series* from UWS is a lower-profile box with lids opening to a full 90 degrees; thus easily allowing it to be loaded with large and bulky items. Two super-duty lift cylinders help raise and hold the Structural Foamed Lid* open. Single lid boxes are the most popular selling box because of their large capacity and easy to use features. UWS boxes are built like vaults secure and sealed against the elements.