This electrical panel includes factory-installed 100A/24 circuits and a main breaker. Distributed neutral bar - plug-on neutral square D service entrance loadcentres are engineered to accept the pigtail less arc fault circuit breakers. Space saver (Tandem) breakers allow you to easily expand the loadcentre capacity CSA approved for vertical, horizontal or inverted mounting and suitable for Al/Cu conductors. Tin plated copper bus bars. Main Wire Size - AWG/kcmil Al/Cu: #4-1. Includes latch door on the cover. This product is backed by a limited lifetime warranty.