Regency shelving is designed to work with many popular brands of shelving, including Metro Super Erecta and Advance Tabco. However, it's important to note that each type of component must be from the same brand, due to minor variations in size between brands.
For example, you can use Metro Super Erecta shelves with Regency posts, but all of the shelves must be Metro and all of the posts must be Regency. However, you cannot use a few Advance Tabco shelves and a few Regency shelves on the same set of posts at the same time, or two Metro posts and two Regency posts on the same shelving unit.
Shelf ledges are sized to fit between the posts on a shelving unit. To make it easy to match up the correct size ledge to your shelving, they are listed so their length corresponds to the length of the shelf that it will be installed on, even though the actual length of the ledge is a bit shorter.