The core design produces good power on the stock head pipes, but should be able to create even more when the rider decides to build more power with either a larger engine or standard industry hop-up parts Provides enhanced sound and improved tunability for performance gains 50-State legal (declared manufacture replacement part) Made in the U.S.A. Black outer tip, gloss black inner tip. 4" versions for M8 use a 2-1/2" louvered cores. Marca : COBRAReferencia del fabricante : 6277RBColor/acabado : NegroDiámetro exterior : 10 cm (4")Estilo de tapa final : Straight-CutEstilo/color/acabado de tapa final : Negro, Brillante, MecanizadaModelo : NH SeriesNombre de producto : SilenciadorUnidades : Pareja