Keep your Cortana Chip Close. A highly detailed and sculpted Cortana Chip from the popular first-person shooter video game Halo 4 , the Halo 4 Cortana Chip Light-Up Key Chain features 4 blue LED lights , Just press and hold the 'on-off' button to activate the lights. The Cortana Chip key chain features a plastic outer casing with acrylic sheet embedment, and measures 2-inches tall x 1 1/4-inches long., The key chain is 1/4-inches thick., Batteries are not replaceable but have a 60 hour light-up life., Ages 8 and up. Battery is not replaceable.