Hard to find spark plugs so this listing was a great find for my needs as I only needed four plugs but hey having two backup plugs was worth it, IMHO. I remember these plugs well but was shocked to learn they are hard to find now. I used them in a Wisconsin VG4D engine in my CASE 1537 Skid steer. All Plugs must be gapped before using., they are not pre gapped people.. Every vehicle has different gaps/needs. Anyone who doesn't do this is just asking for issues as in poor economy, poor acceleration and even poor starting issues.. IMHO. It's super simple to gap a spark plug.