This hitch adapter is designed to be used on a "basher" style truck. To use this piece, simply drill holes through the recessed bosses as seen on the part. Then, drill matching holes in the rear bumper/skid plate on your "basher" style RC truck and then screw or pop rivet the piece in place. From there, drill a small hole through the near horizontal portion and screw in your desired hitch ball. You are now able to pull whatever trailer you desire.
Have fun and be safe!
I used 100% infill as I tend to flip my truck on the rear bumper a lot. Hopefully this will be strong enough to withstand the abuse I put my truck through. If you are gentler on your rig, you can probably get away with 30 or 40% infill and have plenty of strength for your pulling needs.