Neck shims for a Precision bass in 3 different angles: 0.5 - 0.75 and 1.00 degrees. to change the angle of the neck and to lower the action (height) of the strings. worked fine for for me printed in carbon fiber PETG with 100% infill and a layer height of 0.1mm
neck side thickness: 0.3mm , body side thickness: 1.15 - 1.60 -2.00 mm
The author hasn't provided the model origin yet.