Personnel in the store were great, but not the Rain Cap. The rain cap's hinge was binding. I had to open it up a bit so the cap would open and close, then add a second nut to lock them together so as not to vibrate loose. My exhaust stack is exactly 4 inches OD. The cap's bolt and clamp were too short. After I opened the clamp up, I had to substitute a longer bolt and bend it so that it could go around the pipe and attach. It is a good product after some modification; however, it didn't initially fit as advertised.

Picture shows it black it is not as pictured it is bright shiney gal. metal as my exhaust pipe is black it sticks out like a sore thumb.