Plastic construction eliminates danger from broken glass. Small attached bellows. There are no parts to calibrate, warm up, sterilize, or clean. Irritant smoke is the only OSHA-accepted qualitative fit testingmethod that does not rely on the test subjects subjective response. Each VeriFit Irritant Smoke Generator is a complete, safe, ready-to-useOSHA-compliant fit testing kit. Contents: 10 smoke generators, manual,& storage box.