This isn't one of those, products that you immediately think, hey I want that for my Jeep, but rather a necessity if you've had rear shock mount problems. If you've assembled your own shocks, even though the name "bar pin" might not strike a bell, you'll surely remember the piece of metal you had to painstakingly jam through the top rubber shock bushing.
At the time, you may have not been thinking about anything else except your goal of somehow getting a squared object through a much smaller round hole, but that piece of metal as you may have accidentally-correctly called it, is in fact, "a piece of %@#!" It's simply a hollow piece of thin metal, rolled and weld seamed to create a weak damage prone mount.
Dana's Wrangler was the first to have one break , and her lift and shock manufacturer, Full-Traction, after hearing that her's had snapped (on-road), just said, "There's not a 4x4 shop near you anywhere in Phoenix you can pick that up yourself?" I just can't seem to get enough of those guys.
Anyway, we decided to find something stronger out there so it wouldn't happen again. We found that JKS made a Bar Pin Eliminator for the rear upper shock mounts. It is advertised as a way to preload the bushing and to prevent shock noise, but we thought the best feature was that it came with a solid premium grade zinc plated steel bar to replace the vulnerable hollow stock mount.
The install is actually much easier than the stock parts too, because: round hole - round pin. The next and last step is to just add enough pressure with a clamp to compress the bushing to slide the securing roll pin into place to hold the outer mounts together. Now the shock bushing is preloaded and will actually last longer even if it were to tire or tear.
Done, and now it will take a heck of a lot more than a few bumps to break the new pin.
Another example of how weak the bar pin mounts are had to do with one of Jared's shocks. We just happened to be doing some maintenance to his Jeep the night before our most recent Sycamore Creek trip. After getting his CB all hooked up we decide to throw on his new stylish (orange) shock boots. When we took off the right rear, we saw that the bar pin had not only bent, but had split all the way down the seam. This had also torn most of his bushing away. Luckily we keep just about everything we take off just in case, so I had one of Dana's old bar pins laying around. That, and a trip to Autozone down the street for a new eye bushing kept us on schedule for our morning's trip.