Overall a good quality product product but it's only as good as what you're using as a base. To get 4 maxtraxs on the pins, they have to be perfectly aligned in both length and width. A little off the mark and you will have to force the pins to lock - the maxtraxs don't compress ad if you force the pin it will deform. I""ve reverted to using ratcheting tie downs on my roof rack instead of the Pins.