This is the upper, front left (driver-side) hinge point for the collapsible-style camping chair. This chair has approximately .640" dia. tubing. The original pieces were interchangeable from left to right, but I beefed the piece up so it will only work on the left. Here are some other pieces for this style chair that you may need: Back Support from CodeCreations http://www.thingiverse.com/thing:21805 Back Hinge piece from EagleApex http://www.thingiverse.com/thing:26757Make sure your extrusion multiplier or feedstock multiplier are set to give a nice solid layer for maximum strength. I used 5 shells and 25% infill, but I have no idea what the best way to go about should be, or if this can even be made durably enough. To get the old part off, you drill need to drill out the rivets. clamp a vice grip on one end and drill the other end with a ~ 1/4" drill until the head is removed. The replacement piece goes on using (2) 8-32 x 1 1/2" round head machine screws and nuts. I recommend a drop of Loc-tite.