Sonim Direct Mode (DM) works with Sonim XP8 and compatible Sonim XPand Direct Mode accessory to communicate when you have no service. With the Sonim DM App, you can talk, text, use maps, and share your location with other Sonim DM App users who are within range when you have no cellular or Wi-Fi service. Sonim XPand DM accessory is required for the Sonim DM App to work with the Sonim XP8 handset.