My experience with the TENDLITE started out with a challenge. The product arrived and was well packaged. I was impressed with the quality of the product immediately. However after a few uses the light was not working and the batteries would not charge. Although i was disappointed it gave me a chance to really get to see how the customer service end of the product would be handled. I sent an email to Lumina Group explaining my problem and a short time later received a reply deeply regretting my experience and offering me a choice of replacing the equipment or an immediate refund of my purchase. I opted for the replacement and received it a few days later. The new unit worked fine and the replacement charger was able to charge the batteries with no problem. My wife and I have been using the TENDLITE for a week and are pleased with the results so far. The companies customer service is impressive and we are hoping with more time to continue seeing positive results for some of our joint pains.