Truck box knob spacer

thingiverse

I use a custom-made PETG printed spacer that pairs perfectly with a sturdy 5/16-inch threaded knob to secure my truck box firmly onto my truck bed rails. To make it work, you might need to drill through the plastic rail covers, but fortunately, my metal rail had a pre-drilled hole beneath them. The spacer expertly centers the box and keeps everything tightly in place, especially when paired with a nylon wingnut or a custom-printed PETG threaded block that I designed myself.