I had the first Infinity/ML version rigged onto some 4x4s in the backyard for about 5 years, but when I got the new ceiling clearance I HAD to have one of these inside, and Rogue no longer sells the $250 Infinity/ML parts (however an identical one is sold by a competitor that clones Rogue products) The Infinity version was nice because the pull-up bars were just straight pipe without flanges. The 45° beams didn't have bolt holes like this design, but instead had holes large enough for the entire bar to fit through. This allowed flexibility, you can use any rack regardless of width and all that would change is how much the bars protruded out the beams (this is nice if you prefer a narrower rack, or you if you made a wide outdoor DIY rig). The downside is there were only 4 holes so you couldn't adjust the spacing or introduce more bars, nor could you use a fat bar. Another downside is the 45° beams were welded to the center of the bracket, so you could not have it extend from the very top of the rack. It would have start at least a foot below the top of your rack/rig. See crude MS Paint drawing. This ML version is great, but it was the hardest part about assembling the rack. I did it by myself with a 4 foot ladder, but I strongly recommend two people. I mounted mine as high as it can be mounted on my 90" tall HR-2 - which is actually 1 bolt hole away from the highest hole on the upright. You can not attach to this highest bolt hole as the bolts from the top crossmembers are in the way. This is actually where it's supposed to mount anyway, because at this position the angle bracket piece sits flush with the top of the rack posts. I have 10'7" ceilings (10'6" after subtracting rubber flooring) and it baaaaarely misses the ceiling. It's credit card close. Based off the previous review, I thought I'd have more clearance since he has a ~10' ceiling and only bolted it 1 bolt hole (2" space) below where I did. So I'd venture to guess he actually has closer to 10'4" ceilings. If you're not sure if this will fit, you can always bolt it lower - although personally I'd want to bolt it as high as possible and cut/shorten the 45° beams to fit. This way it wouldn't interfere with OHP or doing pull-ups on the regular part of the rack. Pros: The extra height that's possible with this ML version is a plus. Also, you have bolt holes all the way up, so you can customize your spacing, use as many or as few bars as you want, and include any kind of bar (fat, skinny, multi-grip, socket, etc). Cons: Biggest downside for me is the 43" pull-up bars, which locks your rack width in to 49" - too wide in my opinion. You'll be bumping the barbell collar and plates against the uprights on your rack all day. If you have 42" or 41" crossmembers/pull-up bars (ie from another company) you'll need to make a decision. Either adapt to Rogue's 43" wide spacing, or throw away all the pull-up bars that come with this and buy new ones to match your rack width - and it's hard to justify that paying as much as you do for this kit. At $380, this is 65% more than the original Infinity/ML design costing $250 - and 2x the price of the chinese knock off.  You'll notice from the sketch that the last pull-up bar does extend past the footprint of the rack. Before purchasing, I thought this could be sketchy, but I have not found this to be an issue at all. If you look at others, they attach the entire thing in front of the footprint of the rack (albeit they have bigger/heavier racks) - whereas mine is just a few inches.

I highly recommend adding this to your rack if you have the ceiling height for it. It adds a nice twist to your regular pull up regimen and gives you more flexibility for hanging accessories. You will need to pull with much greater explosiveness in order to jump to the next rung on the ladder. I get sore with fewer reps than regular pull ups especially if you control yourself on the descent. Just a few times up and down the ladder per set is enough for me currently. It adds a fun factor not present with regular pullups and you feel more athletic and explosive. Height-wise, I measured from the very top of the flying pull up bar arm to the floor and its almost exactly 10' (less than what Rogue states it would be). The reason for this is there are a few different heights you can mount it on the uprights and I have it on the lowest height due to my 10' 2" ceilings. My RML-690 is not bolted down and with weight on the storage pegs there is no movement at all. If you are going to mount it to a 4 post rig I would definitely recommend it be bolted down. One of the main benefits is that you can hang rings and other accessories off the setup at different heights and away from the uprights. I have my rings attached to the highest bar and my econo tri and lat pulley attached to the 2nd bar (perfect height for tricep extensions). For the rings, I was hoping to be able to do a muscle up from a dead hang, but the added height was still not high enough. At 5' 10.5", I would probably need another 6" of height to make it work. The only things to note are: 1) if you have an RML-690C or any rack with black zinc bolts, you would need to pay for a black zinc bolt kit separately if you are OCD like me and want your hardware to match, 2) you will likely end up scratching the front of your uprights where the arms meet the uprights and 3) I'd recommend having 2 people to install this. I did it myself and holding the pull up bars in place while inserting and tightening the bolts was not easy.