I've had a couple different versions of this in the past. Not bad if you're lighter in weight. I think my latest one was Gold's Gym brand. They're all basically the same. Never broke a door jam and I think the heaviest I weighed while using one was 225lbs.

Had the pleasure of testing this bad boy out at the Mecca (Massenomics gym). Pretty neat and can simulate the stress of carries without worrying about your arms. It was uncomfortable but it makes you want to move quicker.

Price is pretty high for what it is. Knurling is passive but I'll take this at a commercial gym over most barbells they typically have. Wouldn't recommend for the price considering there are several cheaper better options.

My mom had one of the when I was a kid. When I was a teenager and trying to get show me muscles I used to use one of these every night. It's a little gimmicky but if you focus on flexing your abs it's not a terrible workout. Obviously better things you can do for your core but when you're a teenager you just want those 6 pack abs.

If you're going to get the fringe mammoth belt squat you have to get the kick stand. Makes getting belted in and started much easier. You can snag it for free with their sales occasionally.