For Monokey boxes, you'll need a SR3101 kit, which comes with a metal adapter plate which you'll need to fit first. There's also an aluminium plate SRA3101 which is a more expensive option. For Monolock boxes you'll need a SR3101M plate which will then take the universal Monolock mounting plate supplied with the box. I use a Kappa 36l Monokey box - similar to the Givi Trekker but a bit cheaper. Monokey boxes are a bit sturdier than the cheaper Monolock range. Both are easy to fit on the V Strom rack (mine's a '15 plate).