A set including 1 squeezer + 2 masks (1 small masks, 1 large mask) Squeezer dimensions: 15*8.5cm, small mask dimensions: 10*8*6.5cm, large mask dimensions: 13.5*10.5*8cm Instructions: Fully fit the mask to the face, rapidly squeeze the squeezer up and down with one hand, perform multiple compressions. Our anti choking| device training products is easy to use. Under normal circumstances there is no need to replace the device, only the facial cover needs to be replaced every 2‑3 years Noninvasive suction emergency| aid device Helps train your expertise, that saves lives in airway obstruction |emergencies, simple and practical in daily life Plunger for generating negative pressure, more powerfully out obstructors. Vent valve for dscharging air from main body to ensure it can generate strong suction comfortable to wear. Small and lightweight, easy to carry, perfect for travel use