This is a pair of thermactor plugs for Small Block Ford engines.
These are useful when installing a pair of emissions legal heads on a non-emissions car. All OEM and aftermarket Ford smog legal heads have thermactor holes, one on each side of the head.
This is for one pair of plugs. Unless you already have some plugs (such as when deleting the smog pump on your stock heads) you will need a total of 4 plugs, 2 per head.
Compare to Summit Racing/Trick Flow at almost $10.00 PER PLUG!
Some of these are silver in appearance, some are black hardcoat, all work equally well.
One pair Ford thermactor plugs.