This is a Sonos Roam holder that takes the place of the bottle holder (bottle cage) on your bicycle. It should fit standard bottle cages and use the M5 bolts that come with your bike, but I left some wiggle room for the bolt placement. It is friction-fit and I have not had mine fall out after many miles of bike riding, but I may update it in the future for a strap or something. A little electrical tape on the lip can help add friction as well if you want it more snug or if your bottle cage is at a more treacherous angle. Blast some bike tunes!