This adapter bolts directly to your SW-Motech Alu-Rack and serves as the perfect mounting surface for a Coocase S50 Astra basic edition. Also works with S48 Basic Coocases for all you old school riders!If you've already got an SW-Motech Alu-Rack on your bike, and you're planning on mounting a Coocase, then this is the adapter for you! This sturdy adapter eliminates the need to use other special adapters and a universal plate to mount a Coocase to the Alu-Rack. The quick-release design allows you to easily install and remove the plate from the Alu-Rack in seconds by turning the three quick-lock fasteners. Everything is included, no need to purchase any additional hardware.