This tool makes it possible to load your GBB mags using the Vanguard Speedloader. With an easy fit it slides over the in- and output tube of the Vanguard Speedloader and holds on there with the use of a magnet. Also an advantage when storing it inside the Speedloader. This product is also offered through the download tab where you can download the 3d model and make one yourself. Please ask us if you have a special magazine that requires an adaptor. We will be challenged to make it fit.