In the case of heat or fire, the fire pad develops a high volume expansion (20/1) and a high expansion pressure which causes the complete closure of an opening within a short time in order to prevent the transition of smoke and fire.
Intumescent pad packs are labelled to show they are tested to AS1530.4-2005 and AS4072.1-2005 and are available in two sizes.
Datasheet
Power Pad