Sinaflex -221 is a one-component, moisture-curable, polyurethane-based, elasto- meric adhesive sealant. It is a fast curing, non-sag system. After curing, it provides a permanently elastic bond to fasten materials with different coefficients of expansion. 
Advantages

Good Adhesion to a wide range of substrates.

Cures rapidly to a permanently elastic consistency with excellent cut and tear resistance.

Low odor, non-staining.

Surface paintable with water, oil, and rubber based coatings.

Non-Corrosive.

Provides shock resistance and vibration damping.

Exhibits high recovery (> 90%), making it ideal for sealing dynamically moving joints.

Weather resistant.

Resistant to road salts.