4pc socket stud screw extractor remover installer with roller bearing

* Heat-treated, chrome molybdenum steel for long lasting service.
* Chrome-plating for easy cleanup and professional look.
* Corrosion protected.
* 1/2" drive.
* These stud extractors are the concentric roller bearing type that won't damage the thread on the stud.
* It can also be used with 21mm spanners with the hex drives on the top of the socket.
* Integrated concentric roller bearings stud extractors.
* Hex ends allow use with 21mm spanner.
* Can be used to remove or install studs without damage to the threads.