409 is a 8.5 mil, aluminum foil/glass fabric laminate with a high temperature silicone adhesive. The aluminum foil provides excellent reflective and conductive characteristics in high temperature applications. The silicone adhesive provides excellent adhesion at high temperature yet will remove cleanly. They are used primarily as masking tapes in plasma flame spraying. They are also used in applications requiring heat shielding, such as harness wraps.