SummaryEDIT: updated with newer design This is the a-arm for the 1/10 scale 4x4 traxxas slash. it has the normal mounting holes in the front for the shock, but it also has mounting holes in the rear so you can mount another shock to the rear of the a-arm (for the rear a-arms only, steering gets in the way on the front) using my printable extended rear shock tower to mount the shock to (once im done designing it) the weak point of these part is the 4 holes where the pins go to mount the a-arm, you need to have your printer settings just perfect to get the best layers surrounding those pin holes for the highest strength.