Incoming Call LED Flash Alerts Feature With a simple set up in your iPhone, the Incoming Call LED Flash Alerts remind you of calls, attracting your eyes immediately in dark, noisy places or daytime. [To activate the LED Flash Alert feature: Settings > General > Accessibility > Turn on "LED Flash for Alerts"] Note: NOT compatible with iPhone 5C Alixo Specifications: Dimensions: 5.1 x 2.5 x 0.4 inches Be sure to find the official New Trent logo to ensure a 10 month warranty.