Yes this fits snuggly on the Rep 3x3 rack (I used a little UHMD tape to avoid it scratching the rack over time Yes it is great for the forearms, and is built extremely well. The package was delivered promptly, and safely protected all items extremely well. Two negatives, but still a five star review, the strap is a bit long, and Im 6'2", so you have to get creative to reduce it around weights, otherwise there's some lag at the end of each moment. And after a few weeks of use you may need to add oil to as it sqeaks a little. Overall I'd recommend this wrist roller for the rep 3x3 rack.