Housing of a drug delivery device

A housing for a drug delivery device, comprising:

• a first housing component adapted to receive a cartridge at least partially filled with a medicament,
• a second housing component adapted to receive a drive mechanism to operably engage with the cartridge for dispensing of a dose of the medicament,
• wherein the first housing component comprises an insert portion to be inserted in an axial direction into a corresponding receptacle of the second housing component, and
• wherein the insert portion comprises at least one radially outwardly extending first interlock member to positively engage and to lock with a correspondingly shaped second interlock member of the receptacle to rotationally fix the first and the second housing components with respect to each other characterized in that,
• the first and the second housing components are mutually assembled by a snap-fit interconnection, wherein an interlock of the first and the second housing components is of inseparable or non-detachable type, and wherein
• the second interlock member comprises a circumferentially extending groove comprising a wave-like undulated structure and having at least a first groove portion and a second groove portion circumferentially adjoining the first groove portion and wherein the first and the second groove portions are arranged axially offset from each other and wherein the first interlock member comprises at least one radially extending lug to engage with the groove.