MCT Brattberg Spare Blank Filler Block is manufactured from Lycron (a synthetic polymer). Used to fill unused space within frames. This leaves the option of fitting new cable in the space in the future. Developed to withstand fire, explosions, temperature variation, ageing, radiation and rodents. Self extinguishing and do not release corrosive gases when subjected to fire. They are self-lubricating to facilitate installation. Moulded to tight tolerances ensuring uniform and accurate sizing and preventing displacement after installation.