These Chassis control up to 16 modules with as many as 32 two pole relays per module allowing 1xN multiplexers up to 1020x1, 2 pole muxes up to 512x1 or 2xN matrix configurations up to 256x2. Jumpering option allow the modules to be controlled as separate smaller muxes, i.e. 64 4x1 2 pole muxes, or combine specific groups to allow an almost unlimited combination of sizes. Add a Control Module and optional manual control to complete the system.