Comfytemp Red Light Pad for Body, 14.4'' x 6.1'' Near Infrared Light Wrap, Wearable Flexible Soft Light Pad for Back Knee Joint Muscle, 660nm & Invisible 850nm(Corded)

> Sst20 deep red is 660nm and the most common LED to find. agree Convoy T5 is an inexpensive option w SST20 DR Im also a fan of the Sofirn ST10, it has the same LED.. I think this panel is also a good deal https://www.amazon.com/dp/B0DZGPL59G/