Trident Case AMS Exo Series Case for Samsung Galaxy S4 - Retail Packaging - Green Perseus A.M.S. is required in order for the Kraken A.M.S. Exoskeleton to transform into a Kraken A.M.S. case. Kraken A.M.S. Exoskeleton is not a standalone case. Kraken A.M.S. Exoskeleton features hardened polycarbonate, providing a stylish and rugged surface for maximum protection. Impact-resistant Thermo Plastic Elastomer (TPE) corners of the Kraken A.M.S. Exoskeleton protect your device from accidents. This case Series protects device power-ports and audio-jacks with TPE plugs to keep out dirt and debris, and the built-in screen protector provides the ultimate screen protection. Kraken A.M.S. Exoskeleton includes a lanyard loop, which allows you to accessorize your phone with key chains, charms or other accessories.