UllmanDevices Ullman SG-2 Universal Spark Plug Gap Gauge, 1-1/2" Diameter

I had to put new plugs in me Jeeps so I bought this one. It worked fine as expected so I was pleased. Had fun working on me Jeeps as always. Theres always something to work on with that thing.

The media could not be loaded.  Rub the surface with a China marker or sharpie or crayon to improve visibility. Then rub off on a flat paper towel leaving black in the grooves Otherwise it will be very hard to read with low contrast. It’s about the size of a half-roller. Quite small but simple

Got it as a backup, and works well. It seems accurate unlike some others, and because its finish is so smooth, i can slide the spark plug tip on it just a little harder without worrying about scratching the tip.

This is a spark plug gapper. It is a very basic tool that always comes in handy, as you can use it for anything that has a spark plug.I recommend that every have a few of these around. I have one on my key chain, I put one on the dude that lives on the couch keychain, I put one in my emergency kit, I put one in the shop, and I even keep one in the glove box. Why do I have so many if you really only need one occasionally? Trolls. Trolls eat these. It is the only reason I can figure why they get gone so easily.5/5 I'd buy this again, decent price and I didn't have to leave the house.

First time using one of these. It worked great. Just slide the spark plug onto the rim and twist around till it won't slide anymore...that's your gap. Too big, squish it down on a hard surface. Too small, use the hole in the tool to open it up bigger. The tool is solid metal, a little bigger than a quarter, and feels tough - no way you could break it or damage it, so it will last forever.One tip, when opening or closing spark plug gaps with this tool, use very slight adjustments (like so slight that you can't tell if you moved it) - the tool will tell you if you're hitting the right gap or not.

It's difficult to read. It's not a bit like in the picture that shows darkened numerals and lines. Also, the finish of the tool is not a bit like in the description picture. When using the millimeter scale, the spark plug hits the inner edge of the tool, so I can't read the scale while the plug is being measured. This is likely inherent in all tools of this general design. Accuracy seems good compared to my set of feeler gauges. The gap opener part of the tool seems to work well. However, the design of the tool doesn't provide for decreasing the gap size. I may return the tool for a different brand and/or design.

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It might not be accurate enough.At the specific mark, it could not fit in both into my factory pre-gapped plug and the existing old plug .

This is actually a very accurate gauge. I've used my vernier caliper to verify and it was within 0-1 thou. It's very handy for changing the gap on spark plugs, which I had to do, as the one I purchased from a local parts store did not have the proper gap for my car. I would highly recommend checking the gap yourself on spark plugs,if you changing the spark plugs yourself.

Nice tool ! Precision is almost there. A little difficult to read. Not the same as picture description.

It's about 1"3/4 diameter