This is PFET buffered 555 PWM board that comes fully populated and capable of running up to 4S mod builds. It has 6 thru holes: one for the positive 510 connector line, one for each the positive & negative battery connections, one for the fire switch to n-channel MOSFET line and one for each the wiper and diode sides of a potentiometer set up. Wholesale packs of 40 boards are available for pre-order and will begin to ship 12/17/15 .