Just print the holder and then buy a Batavus bike and a Xiaomi mi4 smartphone to go with it :) No, just kidding. I added a step file so it is easier to change for a different sized phone. Unfortunately this holder probably will only fit certain batavus bikes. My odometer broke ages ago so I thought it was time for an upgrade with slightly more functionality. I included a picture that shows the handlebar lever before i put the bracket on. First open the lever and then you can remove the black plate just by pressing it from the back. It will pop off nicely. Slide the phone holder in the lever and close the lever. Once the lever is closed you the phone holder will be firmly stay in place. My Xiaomi mi4 fits in snuggly with its siliconcover on.