Expansion Fittings are designed to compensate for length changes due to temperature variations in exposed conduit runs. Expansion joints are required when the temperature change is greater than 25°F (14°C).  Utilities cable communications residential airports subways bridges & tunnels mines marinas water/sewage treatment plants pulp & paper industries street & highway lighting food processing plants agricultural parking garages car washes fish plants steel mills Comes with O-rings to prevent leakage Pre-lubricated for smooth adjusting Can be installed vertically or horizontally UL listed