The I-Core DUAL Decoders have been redesigned and improved in 2015. The DUAL-1 and DUAL-2 decoders feature a new slim design, solid copper wires, and a revised circuit design. The DUAL-S Surge Arrester's dimensions are the same as before, but it too now has solid copper wires. Old and new DUALs can be used on the same system without any issues.