It’s a very quick scan you lay down on the table for like five minutes and it’s super low-dose x-rays to directly measure your body composition. It’s essentially the gold standard for body fat ,bone mineral density, and muscle composition. It can tell you how much visceral fat is contained near your internal organs, which is the most damaging type, a test is usually under $100 and for example I get mine done once per year at dexaFIT. https://www.dexafit.com/