I use the unit from Model Products (aka Sullivan) and I think it sucks. The cap that locks onto the glow plug is constantly jiggling around and will not stay tight despite all that I've tried to fix it. I think the dubro one would be better. In fact, I've seen some homemade ones that I think look much better. I may cut the cap end of mine off and solder on some type of clip or maybe even a wheel collar to it. That way it will secure to the glowplug better.