CPR Savers' Micromask Trainer Practice-Valves are disposible, and an affordable solution to your CPR training equipment needs. These training valves are designed to fit nearly all CPR masks, and features an air filter and valve that acts as a barrier and obstructs the flow of contaminants for optimum safety. 50 are included in a bag, and are not individually-wrapped. In addition with other CPR training supplies, such as a mask, or face-shields, these valves give your student the most realistic rescue mask training experience possible as they duplicate field-use rescue valves in both form and function.