Review on Sunex 884504: High-Quality 3/8-Inch Drive Thin Wall Spark Plug Socket - Metric CR-MO Construction by Andrew Grant

First use Inner rubber glued to spark plug. Luckily I was able to detach it from the spark plug. Had to be glued back into the socket. Then it worked properly. I suggest paying more and getting one that is magnetic. Also, I would advise the seller to clearly state the 16mm size in the specs. Do not rely solely on the product photo for sizing.