The 40W desiccator (0-10W in 1/10th watt increments on mono and bipolar) allows doctors to change power settings in one step using the rotary dial or the up/down buttons on the autoclavable handpiece. If you need to use a foot control, just plug it in. There's no need for a separate handpiece and you can still control the power setting from the handpiece while using the foot control. This generator has digital error detection and continually monitors every aspect of the A940's output.