Main lugs loadcentres typically are used as an add-on loadcenter and is connected to the service entrance loadcentre when spaces for more circuits are needed or when the main disconnect is located elsewhere. 12 spaces, expandable to 24 circuits maximum with the use of QO Tandem breakers. Type 1 indoor enclosure with a combination flush/surface trim to meet all mounting situations. CSA approved for vertical, horizontal or inverted mounting. Accepts aluminum or copper conductors. Main Wire Size - AWG/kcmil Al/Cu: #4-1. This product is backed by a limited lifetime warranty.