Initially, I thought I was having trouble with the heating attachment. It kept disconnecting and not producing heat. It turns out that I was confusing the "large flat head" with the "heated massage head." The heated massage head is larger across than the large flat head. Once I inserted the correct head and turned on the heat, it worked perfectly. So far, I'm happy with the massage gun function and speed options. My initial impression is that it's going to be a great tool to help with trouble areas that are difficult to get to by any other method.