SR-Series cabinets, like all B-52 enclosures, include a LIFETIME cabinet construction warranty. Reinforced bracings are used to fortify each enclosure. Acoustic dampening material is applied within the enclosure to reduce standing waves resulting in a smoother frequency response. All six ruggedly-built models are fitted with metal bar handles, protective metal corners, rubber feet, 16-gauge perforated steel grills and finished with impact-forgiving black carpet. Input connectors: (2) 1/4" metal phone jacks. The SR-Series is 100% Made in the U.S.A.