Tango TX1 Single gas detector with revolutionary DualSense Technology, includes two of the same type sensor. DualSense Technology increases worker safety, regardless of bump test frequency, while reducing overall costs. The Tango has a three year warranty which does not include battery, sensors and filters. The CO and H2S sensors are warranted for 3 years from the initial purchase date. All other sensors are warranted for 2 years from the initial purchase date.