QON OEM mounting bases are for the mounting of plug on QO, QO GFI, QO AFI and QO EPD circuit breakers. These OEM mounting bases are available in single and three phase versions. This QON OEM bolt on mounting base is for a main breaker of 100 A at 240 VAC three phase. This unit provides 10 kA breaking capacity based on the circuit breakers installed. This mounting base has 3 spaces for 1 pole breakers. A neutral assembly is not supplied with this OEM mounting base. The QON mounting base is UL component recognized.