Rear main seals are a pain to install. If you push them in just a bit too far, there's no way to pull them back out again and you usually end up trashing the seal. That's frustrating - especially if you don't have an extra seal on hand.
Enter the FM rear crank seal installer. Simply slip the seal over the edge of the crank, put the installer over top and tighten it down using a few of the stock flywheel bolts. When the tool bottoms out, the seal is perfectly installed. A great addition to your tool box. Fits all 1990-05 Miata engines.