Free 

I made a standard Garmin mount for my PR2400 bike lamp after the original Ravemen mount broke. I used this model from Thingiverse of a Garmin quarter turn as a base, and made some adjustments as it was a bit loose. Keep the three screws from the original mount to install the new one.
Printed on a Prusa CoreOne Material: ABS PETG will work too and ASA would be even better. PLA will probably do the job but might not last as long as ABS or ASA ;) 4 walls – 25% infill Supports are recommended for the two small "ears" of the mount.
STEP file included if you want to modify the mount.
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