Hi! The differences between Styles A, B, C, and D are not just the appearance. They are different working modes. For the RF head: the red light flashing pattern is different, so the heat feeling may also be different. Style A: red light flashes continuously Style B: red light flashes every 1 second Style C: red light flashes every 2 seconds Style D: red light flashes every 3 seconds For the cavitation head: the vibration pattern is different. Style A: continuous vibration Style B: vibration pauses for 1 second each time Style C: vibration pauses for 2 seconds each time Style D: vibration pauses for 3 seconds each time The main functions are the same, but each style gives a slightly different treatment feeling.