LOCTITE PL Concrete Non-Sag 10-oz Gray Paintable Polyurethane Caulk in the Caulk department at Lowes.com
Varathane 1 qt. Clear Semi-Gloss Oil-Based Exterior Spar Urethane (2-Pack) 9441H - The Home Depot
Red Devil 0909 Foam & Fill Expanding Polyurethane Sealant, 12oz, Champagne (Case of 12): Amazon.com: Industrial & Scientific
12 Pack of 10 Oz OSI 1256934 H2U White Acrylic Urethane Sealant | Caulk and Sealants, Polymer & Urethane Sealants, Window, Door & Siding | Paint Supply
Masterseal NP1 1-Component Polyurethane Sealant White 10.1oz
Tower Sealants 1801026 Tower Tech 2 White Acrylic Urethane Sealant, 10.1 oz - Pack of 12 - Walmart.com
POLYURETHANE Construction Sealant | DAP Global
Water Based Polyurethane vs. Oil Based Polyurethane: Pros and Cons