Plantronics M210C Headset for Cordless and Mobile Phones with 2.5mm Connection M210C Headset for Cordless and Mobile Phones • Provides handsfree convenience—complete other tasks while you talk • Fits most cellular phones (2.5mm jack required) • Manufacturer’s limited one-year warranty Multi-task at home while enjoying clear conversations with your hands-free headset for cordless phones. Comfortable, affordable headset includes a microphone adjust switch that optimizes sound. Simply plug into existing cordless home phones/mobile phones with 2.5mm ports—it’s that simple to install.