The Plantronics M25 Bluetooth headset features DeepSleepTM mode to stay charged for up to five months, so it"s ready when you want it. You can listen to music, Internet radio, or driving directions and never miss a call. Whispered alerts keep you informed about battery level, Bluetooth connection, and more.Plantronics DeepSleepTM power-saving mode activates when your M25 is away from your phone for over 90 minutes. When it"s back in range (33 feet or less), you can just tap the Call button to "wake" it up. Using the DeepSleep mode can extend the battery readiness for up to five months.