Square D Meter Centres provide a compact and versatile metering and distribution centre for today's residential, commercial, and industrial markets. The 600VAC, 600A main bus bar link connector is a Square D Meter Centre meter stack accessory. Main bus link connects join two or more meter stacks. The first stack or single stack installation doesn't require bus links since the tap box is supplied with main service lugs and bus bar link connectors. The bus links meet CSA standards.