My windshield doesn't have a frame so I had to add a small piece of wood to fill the gap but it clamped on tight to the windshield with no problem. It gives a nice wide angle view behind the boat. The swivel is tight enough that the mirror doesn't move when pounding over other's wakes (unlike the cheap rear view mirror on my UTV). After an hour of crashing wakes it still remained tight on the windshield. I like the metal base for mounting. Very stong.