I recently purchased a universal screwdriver attachment for my Industrial and Scientific power tool set and i am impressed by how versatile it is. Based on my observations it can fit screw sizes ranging from 7mm to 19mm, which is a great range for any DIY or professional project. The attachment easily extends the reach of my power tool and increases its efficiency. The only downside is that it can be a bit tricky to install and remove from the screwdriver.Overall, I highly recommend this attachment for anyone in need of a reliable and efficient tool..