Just before the recent Deep Freeze I decided to test the tool I have to open the cover over the city-water cut-off valve (which is in the front yard). I don't want to be struggling out there in 10 degree weather with water pouring onto the floor indoors from a broken pipe!

It turned out the "key" worked great and lifted the cover right off to reveal ... mud. Nothing could be seen. After some digging with a shovel the valve was eventually revealed.

And there's not much room down there to get a wrench to close the valve. It's doable when the weather is nice, but I'm going to keep an eye out for a better tool since the weather is likely to be miserable if I need to do it.

So my emergency tool works but actually testing it revealed other problems...