Specially formulated for outdoor use, TYTAN Professional Outdoor & Auto foam is similar to our other foam sealants but is resistant to discoloration from UV exposure. This black foam provides a watertight seal, safe for waterfalls and koi ponds, and is used heavily in the RV industry, where the black color allows it to blend in with rooftops and undercarriages. * Won’t discolor * Strong watertight seal * Reduces unwanted noise in autos & RVs * Safe around koi fish