This is Atlantic Water Garden's AWG Black Silicone 2.8 & 103 oz tube. We have a large selection of Installation Tools/Plumbing and other water features from Atlantic Water Gardens.
Manufacturer's Description
Black RTV silicone sealant is used to create a watertight seal where liner is attached to filtration components. Permanently flexible RTV silicone used in conjunction with Atlantic's molded-in inserts, liner retention flanges and stainless steel hardware ensures a watertight connection every time.