Most used metric socket and most lost. They seem to evaporate from any socket set, I've had three 1/4" metric sets with no 10mm sockets. These sockets are well priced and work just like the original sockets they replace. I have all the missing 10mm Replaced sockets on my 1/4" drive sets and have lots of extras when they go. I would buy these (10) 10mm interchangeable heads again.