GUARDIAN AG 540 is a black, one-part high quality silicone sealant that provides a permanent flexible, durable, watertight seal for inside, outside and underneath the car. The sealant is extremely resistant to UV radiation, weathering, ageing and water, and offers excellent chemical resistance and is unaffected by alcohols, dilute acids, alkalis, and detergents. It also performs as an excellent adhesive on non-porous surfaces where an elastic gap-filling bond is required. It has a non-sag rheology and can be applied to vertical surfaces.