Five stars on function and look. The installation knocks a star off. Instructions while technically correct in writing are horrible with photos. Looks like somebody keeps black and white photo copying the one set of color instructions. Photos should be in color, HD, and bigger.Yes a pro with a lift could install these in a couple of hours. Took me about six over two weekends. First weekend I unpacked the box and sorted all the parts and made the first attempt at matching up the brackets. First big mistake was starting to pull fasteners off the rubberized trim on the bottom of my Explorer. YOU DO NOT NEED TO REMOVE ANYTHING FROM YOUR EXPLORER TO INSTALL! The fasteners are shot once you pull them off. Luckily I had some generic ones to pop back in. The other thing to note is THAT YOU WILL HAVE TO DRILL TWO HOLES IN YOUR EXPLORER! I recommend going down 1/32 in the drill bit size they recommend. I went 7/16 and on the first one I thought I may have cleaned it out a little too much since the parts provided barely bit and tightened in. The second whole bit a little more but still did not fasten down to my satisfaction. These holes (one on each side) are mainly to secure the boards from shifting forwards or backwards and not so much for main support. So not too worried about how tightness on the drilled holes.I used a ratchet and standard open ended wrenches to tighten every down. I think I used 16, 17, 18, and 19 mm wrenches. Lots of swapping when you are under there swearing.Boards look great and lots of raves from passengers. I opted for the 5" since the 6" look like they would stick out even from the tire width. The 5" still give me enough purchase so I can stand on them and wash the roof of the Explorer. The 4" would give a nice clean look if you are looking for style over function.