CRC 2105 Smoke Test Brand Liquid Smoke Detector Tester, 2.5 oz Aerosol Can, Clear Aerosol spray extends user reach up to 6-feet allows testing to be done while standing safely on the floor No harmful residue, plastic safe and non-staining UL listed Contains no class I or class II ozone depleting chemicals Checks for obstructions or debris which clog detector vents