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