The Bellows Pump Kit accurately tests ozone residuals in air for concentrations of 0.5 to 300 PPM. The bellows design provides precise volume and flow characteristics for accurate, repeatable results. Easy to squeeze for one-handed operation. Constructed of highly corrosion resistant material with built-in automatic stroke counter. The Bellows Pump Kit includes pump, deluxe tube opener, and soft sided carrying case (detection tubes not included).