MBR9302, Pole 1600A-2000A MCCB mounting block for use with molded case circuit breakers MCCB such as, PD6, HPD6, PXD6, RD6, RXD6 and SPD6 frames. This block allows breaker to be mounted to this block and then bolt to panel for line power. #78364322630. Most other brands use flat bus to connect to their breakers. Siemens provides this base for easier installation and avoids custom bus bending.