Monster M Series M1.4s Mlock Master Pin Biwire Center Channel Speaker Cable (10 ft. piece) (Discontinued by Manufacturer) UL CL3-Rated for in-wall use. Magnetic Flux Tube for smooth, extended frequency response. MultiTwist construction for lower noise floor. PEX dielectric for improved reproduction of harmonic structure and inner detail. Time Correct multiple gauge wire networks for greater clarity.