Kit of personal care appliance and power plug

A kit, comprising:

• a first personal care appliance selected from an electric tooth-brush, a shaver, a charging device, a cleaning station, or an epilator, the first personal care appliance comprising a first housing having a first socket having exactly two connector sleeves, wherein the first socket has a first socket geometry assigned to a first ingress protection class (IPC);
• and
• a first power supply device comprising a first power plug having exactly two connector pins, wherein the first power plug has a first plug geometry assigned to a second IPC equal to or different from the first IPC,
• wherein the first socket geometry is selected from a set of at least two IPC-differentiated socket geometries, each IPC-differentiated socket geometry of the set providing a corresponding socket IPC,
• wherein the first plug geometry is selected from a corresponding set of at least two IPC-differentiated plug geometries, each IPC-differentiated plug geometry of the corresponding set providing a corresponding plug IPC,
• wherein the first socket geometry comprises a shape that is operative to:
• allow power plugs having one of the IPC-differentiated plug geometries with a corresponding plug IPC equal to the first IPC to be inserted into the first socket,
• allow power plugs having one of the IPC-differentiated plug geometries with a corresponding plug IPC higher than the first IPC to be inserted into the first socket, and
• prevent power plugs having one of the IPC-differentiated plug geometries with a corresponding plug IPC lower than the first IPC from being inserted into the first socket.