A CPR emergency can happen at any time, in any place, to anyone. This pocket mask can always be there when you need it. The Marine Sports Pocket Mask CPR Barrier is perfect for both in water diver rescue and out of the water rescue. The mask is fitted with an Oxygen port and has a valve and filter which act as barriers separating the rescuer from the patient. This Pocket Mask is an essential safety device for all divers.