BOYA Microphones Warranty: 12 months product warranty and post-sales service, if you are not satisfied with our product, please contact us. Wide Compatibility --- Suitable for a wide range of wireless applications such as interviews, electronic news gathering (ENG), electronic field productions (EFP), film production, business and educational applications, Broadcast TV, News Gathering and more (Pls note: when work with smartphone, you may need to buy a extra adapter fit for your phone). Headphone Monitoring --- the receiver is built with mic and headphone output jacks. The bodypack transmitter includes a MIC jack and LINE IN jack. Operation Range --- More than 6 Hours Continuous Operation,Operation range can reach up to 100m(300') (without obstacle) (Power supply: two AAbatteries). BOYA BY-WM8 Pro-K2 is an upgraded UHF Dual-Channel Wireless Microphone System for capturing audio with dual subjects, features an easy-to-read LCD display, a wide switching RF bandwidth, PLL-synthesized tuning and digital companding circuitry.