3", PVC Electrical Conduit Expansion Coupling, Designed To Compensate For Length Changes Due To Temperature Variations In Exposed Applications Of Conduit Runs, For Use With Schedule 40 & 80 Conduit, Features Exclusive Molded In Mid-Point Indicator On The Piston, Exclusive 3" Expansion Fitting With 8" Travel Distance, 2 Piece Molded Design With Lubricated Seals For Easier Movement For The Life Of The Product, Ridges On The Fitting For Easier Installation, 2 O-Rings To Prevent Leakage, Can Be Installed Vertically Or Horizontally.