The issue I have with them is that they are, or were, selling lb7 and lly glow plugs as the same. They are not the same. I purchased a set not realizing that they didn't know this. Well after lb7 glow plugs fail to heat on a 4.7 volt system, I called them and they told me I'm the nut job who doesn't know what he's talking about. Then out of a "professional courtesy" they'd refund my money so I could take my business elsewhere. They told me their engineers are not aware of any differences and that they would "look into it".