A pin nailer sets a 23 gauge headless nail (pin) in wood. For the last 30+ years, I have been using a model made by Senco. I primarily use it to fasten face veneer to the edge of plywood during glue-ups to hold everything in position until I can apply clamping pressure. The pins are so small that they need not be filled later. This weekend, my Senco started spewing plastic guide bushing fragments rather than dispensing nails. I tried to locate a repair kit but had no luck with a nailer of this vintage. Pictured above is the unit I replaced it with which arrived today not a moment too soon. I really like the size and weight as well as the firing action. I will have to adjust to the double (safety) trigger. My old unit had a single trigger and would fire a nail indiscriminately whenever it was actuated whether into a piece of wood or through the air or into a body part. The new unit will do all of these things but only if you sequentially pull the first and then the second trigger. At first I found this annoying and started looking for some tape to bypass this feature. Upon further reflection, I decided the added margin of safety was worth the nuisance.