Arctic Hayes Classic 9g Smoke Cartridges are encapsulated in a polycarbonate plastic sheath. Perfect for testing air filters, fume hoods, air balancing and fans, as well as for use within mandatory testing of flues, chimneys, pipe and ductwork. White smoke can also be used for photography, special effects and more. Each cartridge supplies approximately 7m³ of dense smoke for 75 seconds. Supplied in a resealable plastic pack. Complies with BS 5440-1.