Wilson Electronics Mobile 4g Cellular Signal Booster Kit - Retail Packaging - Black (Discontinued by Manufacturer) Significantly Boosts Cellular Signal Strength For Both Voice, 3g & 4g Data Inside Vehicle No Physical Connection To A Cellular Phone Or Cellular Data Device Is Needed Amplifies Signals Both To & From The Cellular Tower Max 2,500mw Output Power Works On All Generations Of Cdma & Gsm (3g & 4g)