Hi sir, Even though our this device only has 2 Tens ports, but as I told you before, we also have control boxes, which can turn one output port into two output ports, so they can turn 2 tens ports to 4 tens ports if you use our control boxes, I've attached its picture below, pls check it when you're free. Except tens function, it also has TCM hot compress penetration therapy and infrared laser therapy. https://www.youtube.com/watch?v=iJ6f2r0J73g Our this Youtube video shows how to use it, pls check it if you want. Thanks for your trust, wish our this device will help you a lot. Best Regards, Alice