Bosch tools are usually a safe bet in my opinion. This extension is garbage. The set screws are smaller than any extension I've ever used from any other brand. At first it seemed like an inconvenience because I needed a second allen key. On first use, one of the set screws came out and got stuck in the hole I drilled while scraping the hell out of the outside of the extension. In later use I tightened the remaining set screw more than I would like it not to fall out - still falls out no matter what. Stop at another brand. waste of money here.