Replacement accessory kit for use with the ModuLaser range of products. The kit comprises of: A interconnecting ribbon cable, for use between modules, 2 x Interconnecting clips, for use when modules are installed sideby-side, 2 x Bus termination end-of-line units, 7 x Pluggable connectors, for use with the various connections on the ModuLaser backplane, 2 x End-of-line resistors, for line monitor on the inputs of the ModuLaser.