The Forward Control Take Down Pins are a simply designed set of AR15 and M16 pivot and take down pins. They are machined from a 17-4 PH SS bar stock and QPQ finished, these pins are 0.040 longer than TDP spec pivot and take down pins.
 
PF-040 pins have been appropriately described as "reverse extended," in the sense that they are longer on the left side of the receiver. The additional length of the take down pin does not impede with an ambidextrous safety operation. When the PF-040 pins are pushed in from the left side, the +0.040 turns into extra length and gripping area on the right side pin head making it easier to separate an upper and lower receiver. 
 
The PF-040 right side pin heads (when installed on a receiver with the muzzle pointing away) are flat, with a small 45 degree chamfer. Serrations or dimples on the right pin head would be not serve a purpose, so they are completely bare. There is a small dimple on the other side of the pin head and the tip of bullets up tp 9mm can be used to push the pins out on tight fitting receivers. 
 
The PF-040 may not work on stocks that have bars overlapping the take down pin holes.