Features: 1. CPR trains mask valves to avoid direct touch rescuers in the patient's mouth, nose, and face. 2. Friendly design can effectively protect rescuers and help to eliminate hesitation in cardiopulmonary resuscitation. 3. Oxygen intake helps to increase the patient's oxygen delivery. The standard connection is 22mm. 4. When using the CPR mask for classroom teaching, a CPR mask training valve is an economical and effective alternative. 5. It is suitable for most CPR masks. For training purposes only. Specifications: Material: PVC Size:22 mm diameter Function: Emergency Rescue/CPR training Weight:30g Color: Transparent Package Included: 2pcs* CPR mask valve Note: 1.Due to the different monitor and light effects, the actual color of the item might be slightly different from the color showed in the pictures. 2.The color of the product is subject to the color received, please allow 2-4cm measuring deviation due to manual measurement, thank you for your understanding!