FYI, these aren't the Foot Tractor boots. They are the Patagonia Rock Grip Aluminum Bar boots. The Foot Tractor came after these. I personally think these offered better traction than the Foot Tractors once the bars broke in and got roughed up a bit.
If you need this kit, it means you’re fishing a lot. It contains everything you need to repair your Patagonia built by Danner® Foot Tractor Wading Boots.
The replacement kit that I posted is a replacement kit made for both the boots for sale here and the original foot tractors. Here is a five star review on the kit from Patagonia's website saying as much:
I’ve been using these wading boots with the straight aluminum bars for several years. They provide great traction, are very easy to walk in and don’t damage floor surfaces if you walk delicately. Replacing the bars is best done with a claw hammer. You pry them right out of the boot. The replacement kit has the receiving plugs which must be screwed into the sole before setting the bars. Great product."