What a belt does
What a red light therapy belt is for
A belt is a flexible LED strip, usually 660 nm red and 850 nm near infrared, sewn into a wrap with a strap. It holds the LEDs flat against the lower back, abdomen, hips or thighs at zero distance, which is the highest irradiance any wearable can deliver, and it frees your hands for 15 to 20 minutes. People buy belts for lower back and core comfort after activity, for daily sessions they will keep up because the belt goes on under a shirt, and as the body-contouring add-on marketed as "red light therapy for stomach".
On that last use: red and near infrared light at these intensities is studied for skin appearance, circulation and recovery. A belt is not a weight loss device and no belt here is sold as one. Clinic-grade body contouring is a different category of equipment, covered on the Body Sculpting and Laser Lipo pages.