P3 P3 P4250 Kill A Watt CO2 Wireless Includes P4255 Kill A Watt(r) Co2 Accessory Sensor & P4225 Display allows User To Calculate The Carbon Footprint Of Appliances Monitors Power Consumption Remotely Within A 300ft Wireless Range Calculates Carbon Emissions & Costs By The Day, Week, Month & Year Can Be Used With Up To 8 Sensors