In looking into some of the possible benefits of this treatment, I found that though still technically unproven, there have been well documented studies that have produced evidence to suggest that Red Light Therapy may be effective for:1. Improving skin complexion and building collagen. It has been shown to diminish wrinkles.2. Reducing some of the side effects of cancer treatment.3. Relieving pain and disability in degenerative osteoarthritis of the knee.4. Lessening pain and inflammation in people with pain in tendons.5. Promoting wound healing and tissue repair.The problem with putting this belt on a knee or elbow is that you really need to have the joint straight for it to work well. It is not made of a flexible material that will bend with you joint. I love that it is cordless but it really can't be worn while you're doing much of anything so maybe having a cord would not be as big a hassle as I thought. It seems to hold a charge quite well. It goes through 10 or so, 15 minute runs before it needs recharging.This RLT belt has 2 modes: On and off. There is no way to select the power level. There's not a timer. These are features that you may find on other RLT devices. This light does have a 15 minute automatic shut off feature.This unit can be charged via a USB power adaptor. It does not come with a case to store it in but does include a sturdy box. This is ok but I wish it came with a hard case and therefore doesn't seem as professional. Besides the box, the item only includes a USB-C charging cord and a page of basic directions.Conclusion: All in all, this device is a well made. I believe it has benefits for pain relief, skin rejuvenation, reducing inflammation and wound healing. My wife has arthritis in her knee and has found that using this every evening before bed to reduce her pain at night and into the next day. I have also been using this for my lumbar spinal stenosis and for relieving soreness in my forearm from an injury a few years ago.