This CPR pocket mask is a great addition to any first aid kit. After becoming an EMT last year I learned the importance of maintaining A. the airway, and B. body substance isolation, and this collapsible mask goes a long way in achieving both. The soft plastic bubble that lines the mask creates a great airtight seal when fitted over the mouth of the patient ensuring effective oxygen delivery. In addition, the two way valve minimizes the rescuer's exposure to any bodily fluids or vomitus that could result from providing rescue breaths. The mask itself is standard equipment in trauma bags, and the oxygen port can be used to attach an Ambu bag or oxygen line. [UPDATE Note: Commenters over at Cool Tools pointed out that changes are being made in regards to rescue breaths and CPR and that it is important to stay up-to-date in your training. Despite the changes this mask remains useful in many other situations including CPR.-- OH] -- Oliver Hulland CPR Pocket Resuscitator $7 Don't forget to comment over at Cool Tools. And remember to submit a tool!