Square D QO 100A Indoor Main Breaker Plug-on Neutral Load Center Type QO load center with cover and main breaker installed. Plug-on Neutral ready and built with a shielded, copper bus bar that is plated for reliability. 100 amp main breaker included. Ideal for residential, commercial, and industrial power distribution. Engineered for fast installation and wire savings. UL Underwriter's Laboratories listed for residential, commercial, and industrial power distribution. Series QO, Amperage 100A, Number Of Spaces 24 Spaces, Max Number of Circuits 24 Circuits, Voltage 120V/240V, Enclosure Type Indoor, Mount Type Combination, Phase Single, Wire Size 4 #1 AWG Copper, Aluminum , UL Listed Yes, Pkg Qty 1, Package Type Box WARNING This product can expose you to chemicals including lead which is known to the State of California to cause cancer and which is known to the State of California to cause birth defects or other reproductive harm. For more information go to www.P65W