Bluetooth sync with mobile devices. This set contains Walker's Razor Slim Quad Electronic Earmuffs with Ultra Low Profile Ear Cups (Black), Limited 1-Year Warranty, Walker's Razor Tactical and Hunting Walkie Talkie Attachment, 2 x Aaa Batteries, Walker s Gel Ear Pad for Razor and Xcel Series Muffs with Comfortable Design (Black), and Limited 1-Year Warranty.