A lovely little tube of joy. Made from the good type of silicone.
A tiny, gentle shmear on your injector seals will keep them from binding when you install them into the fuel rail and into the manifold, a bit on your distributor shaft o-ring to let it seal properly, a nice thin coat on your distributor cap seal to keep out the moisture, a tiny dab onto the spark plug boots (cap side and plug side)..... Keeps out water, dirt/dust and makes everything removable again.
I wouldn’t recommend it if it didn’t actually work. It has a million uses around your shop and house. Slicker than snot, works on anything. A little goes a long way.