3nd example with the use of TULAS.

The flexible loop connection is made with a few cm's of TPU filament.

Pause at 5.8mm to add the magnet Ø8x5.

For more info on TULAS, how to connect the filament and how to use it with your own models: 

TULAS: the universal hanging/strapping system

Note: As a TPU filament I tested with Ninjatek Ninjaflex which has a hardness of 85A. If you use TPU with a higher hardness (e.g. 95A) you cannot pull such tight knots and the chambers for the knots are too small. So use TPU of 85 Shore or lower.