Abstract: A fastening device for releasably fastening a functional unit in a connection direction to a receiving unit. The fastening device comprises a functional unit comprising a functional unit abutment surface and a receiving unit comprising a receiving unit abutment surface. The functional unit abutment surface and the receiving unit abutment surface are configured to abut against each other in a connected state. The fastening device comprises at least one pair of magnets comprising at least one functional unit magnet allocated at or within a proximity to the functional unit abutment surface and at least one receiving unit magnet allocated at or within the proximity to the receiving unit abutment surface. The at least one functional unit magnet and the at least one receiving unit magnet exert an attractive force to each other.

Abstract: A fastening device for releasably fastening a functional unit in a connection direction to a receiving unit. The fastening device comprises a functional unit comprising a functional unit abutment surface and a receiving unit comprising a receiving unit abutment surface. The functional unit abutment surface and the receiving unit abutment surface are configured to abut against each other in a connected state. The fastening device comprises at least one pair of magnets comprising at least one functional unit magnet allocated at or within a proximity to the functional unit abutment surface and at least one receiving unit magnet allocated at or within the proximity to the receiving unit abutment surface. The at least one functional unit magnet and the at least one receiving unit magnet exert an attractive force to each other.

Abstract: A magnetic fastening device for releasably fastening a first unit and a second unit to each other. The first unit has a first unit abutment surface. The second unit having a second unit abutment surface. The first unit abutment surface and the second unit abutment surface are adapted for abutment against each other. The device includes at least one pair of magnets including first magnet allocated to the first abutment surface and a second magnet allocated to the second abutment surface. The first magnet and the second magnet exert an attractive force to each other. The first unit may be or include a communication device and the second unit is a helmet or a separate unit permanently fixed to a helmet.

Abstract: A magnetic fastening device for releasably fastening a first unit and a second unit to each other, the magnetic fastening device comprising at least one pair of magnets, wherein one of the units is provided with at least one protrusion, while the other of the units is provided with at least one recess for receiving the at least one protrusion, and wherein a first magnet and a second magnet of each pair are displaced relative to each other by a displacement distance in a displacement direction such that, in a state in which the units abut against each other, a component of the attractive force maintains the at least one protrusion in the at least one recess.

Abstract: A magnetic fastening device for releasably fastening a first unit and a second unit to each other, the magnetic fastening device comprising at least one pair of magnets, wherein one of the units is provided with at least one protrusion, while the other of the units is provided with at least one recess for receiving the at least one protrusion, and wherein a first magnet and a second magnet of each pair are displaced relative to each other by a displacement distance in a displacement direction such that, in a state in which the units abut against each other, a component of the attractive force maintains the at least one protrusion in the at least one recess.