I needed a magnetic file holder to stick on the side of my office refrigerator. Designed to be printed on a P1P with PLA basic. Utilizes 9 magnet - push fit slots. I used 12 x 2 mm double stacked, for a total of 18. It does not slide one bit. The pictures of the print show some stringing - either the filament I used or my hot end. All prototypes with different filament looked fine.