Every belt runs two wavelengths. 660nm red reaches the layer where collagen is made and where a belly stops holding its shape. 850nm near-infrared travels deeper, into muscle and joint.

The ratio between them is what decides which job the belt is actually built for. It is the single most important number and it is almost never on the box.

Of the fourteen belts I could find spec sheets for, only five publish it at all. If a company will not tell you the ratio, you cannot know what you are buying. That alone eliminates most of the market.

This is the part that cost me eleven months.

Of those five that publish it, four are weighted roughly two infrared to every one red. That is a recovery build. It is the correct build if your back hurts.

It is the wrong build if the problem is your belly, because most of that light travels straight past the layer you are trying to reach. I had been buying back-pain devices for a belly problem, four times, and nobody had told me.

ThermaLight360 Pro runs it the other way: 210 red to 105 near-infrared. Two red for every one infrared.

Collagen remodelling takes six to eight weeks. That is not marketing, it is how the tissue works.

So the belt has to survive two months of daily use before it has had a fair chance at anything. Mine lasted nineteen days, then five weeks, then never.

Read the reviews on the biggest sellers and the same sentences repeat: broke within a month, the control unit just died, no support past 30 days.

A thirty-day support window is not a warranty. It is a countdown, and it runs out before the thing you paid for has started. Check for a warranty measured in months. This one carries a year.

This sounds trivial. It is not, and nobody mentions it.

Two of my four did not close properly, which is its own quiet insult when you are already not enjoying looking at yourself.

Cheap belts run short because material costs money. Check the stated length before you buy anything. This one is 50.8 inches.

This is the check I would have failed on my own if I were being sold to, so I will be straight about it.

This is twenty minutes a day, most days, for two months before you judge it. If that is not going to happen, no belt on this list will work for you and you should keep your money. That is the honest answer.

What I will say for it is that it asks nothing else. No gel, nothing to rub in, no routine, no appointment. One woman left a competitor's cupping and gel system for this and her reason was not the science, it was “at the end of the day it is a lot of work.”

You put it on, you sit down, and you leave it.