This device disable cellular phone (text/phone/email/app) while the car is in motion. This is a very good idea for many people I see using cellular phone in their cars. It is sully $99 but AT&T is discounting it for $10. It's a bargain. http://www.att.com/accessories/specialty-items/scosche-cellcontrol-safe-driving-system.html?partner=LinkShare&siteId=NKa3hZyYoHA-y_3FFkwRZYC3LSq6kCHuIQ#fbid=1IVGJZq_lbY