The Classic ; System pro M product cannot be intermixed and do not share common accessories. System pro M products can only be fitted to new style Protecta distribution boards,see typically RS stock no. 539-1553. Type B Double Pole 6kA - System Pro M Compact. The System Pro M Compact range of Miniture Circuit Breakers from ABB, for use in Residential, Commercial and Industrial applications with a tripping characteristic of Type B