The ideal RCBO. IMHO, would come as a pack of 12, ready fitted in a neat enclosure, with a 100A 2 pole isolator.all wired up (except for the circuits). There would be enough room in the enclosure to dress in wiring neatly with a bit of slack and accommodate 25mm tails easily. Each RCBO would incorporate DIP switches to select 6A,10A,16A.20A.32A,40A,50A,63A, and a tripping current of 30mA,10mA,300mA, it would also incorporate a self-test facility whereby every month it would perform a 1/2, 1/ and x5, sending the results via tinternet to installers PC. In tghe case of an overload or earth fault,tripping the RCBO, it would search it's circuit for faults and reset if fault cleared. otherwise transmit fault code to installer. Oh, Yes, and all for around a tenner ( once the chinese have got them into production)