Extension bars, sometimes called 'extender arms', allow access to nuts that are difficult to reach, typically in automotive applications.

This Teng Tools extension bar has a 3/8in Square Drive. It is manufactured from chrome vanadium steel for strength and durability, and has a satin finish.

The TENM380022 extension bar has the following specifications:
Drive: 3/8in.
Length: 250mm (10 inch).