This model holds the front fork of a mountain bike with a 15x110 thru axle skewer for bike storage. Four bolt holes allow you to mount the bike for storage in your car, on a wall, or anyware you can get a bolt/screw joint. I used skateboard bolts/nuts, but dimensions for the 4 bolt pockets are in one of the posted pictures. If you plan to use this in your car, I recommend printing out of PETG or other more heat-resistant plastic to avoid shrinkage. The as-modeled length between the dropouts is 4.453"