Question about sealing Windows, and other items

Use Proflex or you can use OSI Quad available at Lowe's or Home Depot.

OSI Quad comes in colors and is used on windows and doors of buildings and houses and I believe it is polyurethane. Worked fine when I replaced the weathered wooden brick moulding around the doors and windows with vinyl brick moldind and a friend with a portable cutting and bending machine did the aluminum flashing.