Lightweight and flexible Convenient nylon case Always be prepared to save a life with Lifekey. The EMI CPR lifekey lets you carry your CPR Lifeshield with your keys or on your belt. The lightweight, clear and flexible CPR Lifeshield has positive one-way breathing tube. The CPR Lifekey comes in a convenient nylon case with a swivel eye-snap hook, which attaches easily to your key chain or belt loop.