This specification covers a one-part, high temperature resistant silicon sealing compound supplied in caulking cartridges. This product is used primarily for sealing aircraft firewall structures against passage of air and vapors. The cured compound shall remain an effective sealant at all temperatures between -65 and +400 degrees F (-654 to +204 degrees C) and shall be able to withstand a flash temperature of 2000 degrees F (1093 degrees C).