Black RTV Silicone sealant is used to create a watertight seal where liner is attached to filtration components. RTV Silicone used in conjunction with Atlantic’s molded inserts, liner retention flanges, and stainless steel hardware ensures a watertight connection every time. Atlantic’s Room Temperature Vulcanization formula cures quickly for a permanent flexible seal. 10.3 oz tube fits on a standard caulk gun.