I need to install a 40 amp mcb and search as I may I cannot find a like for like replacement anywhere. Does it have to be a MEM 40 amp MCB (AB40SB)(Type B) or is there another make that will fit in this consumer unit? It's for a 9.5KW shower and I still have one slot available on the left of all the other MCB'S. See photo in my memera album.