Retention magnet system for medical device

A device, comprising:

• a housing;
• and
• a magnet group disposed in the housing, the magnet group generating a group magnetic field, the magnet group including:
• a first magnet portion that produces a first magnetic field;
• and
• a second magnet portion that produces a second magnetic field, wherein
• the first magnetic field and the second magnetic field contribute to the group magnetic field, wherein
• the device is a medical device,
• the magnet group is a disk-like magnet group,
• the first magnet portion has a first magnetization direction that is different from a longitudinal axis of the magnet group,
• the second magnet portion has a second magnetization direction that is different from the longitudinal axis of the magnet group, and
• the magnet group is configured so that the first magnetization direction and the second magnetization direction are fixed relative to each other.