Hi, I have a machine Digital Auto TENSE model STT-570 (Leo Med II). The rocker switch at the back of the machine is now broken and can only be switched on if someone continue to press the switch when it's on. Do you sell the spares for this switch ? If you do, how can I order? If you don't, can you give me the specs so that I can get an OEM unit. Thank you for your help. Lee