You can buy it any of those places. It is good to have it around and use it on all your electrical stuff.

 

Good for rubber o-rings too. It's real sticky stuff and it keeps them from drying out andseals them upnicely.

 

I put it on every plug I could get to, from plug on the fuel pump on the tank to injectors under the hood.

Under the truck I did the O2 plugs, tranyplugs.

If it had a plug I used the dielectric grease on it.
Just make sure that you replug everything right so it
all reseats.