This is an STL file of the bike adapter that comes with Blackburn's Folsom U-Lock. Mine snapped off during one of my rides to work and I simply recreated the same exact lock but beefed up the critical sections to ensure a stronger part that won't snap under pressure.I printed my model using a 0.010" layer resolution. The STL file is considerably smooth so using a higher resolution printer will only help with building a satisfactory finished (replacement) part.