Dose setting mechanism for a drug delivery device

A dose setting mechanism for a drug delivery device, said mechanism comprising:

• an inner housing having a helical groove along an external surface of said inner housing, where the external surface defines a tube having a circular cross-section and said inner housing comprising a first rotational stop member near one end of said helical groove, where the first rotational stop is cuboid-like projection projecting radially outward from the external surface;
• a dial sleeve rotatably engaged with said helical groove of said inner housing such that the dial sleeve is assembled over the inner housing and rotates relative to the inner housing, said dial sleeve comprises a generally smooth outer surface and an inner surface having a helical groove and a second rotational stop member;
• and
• an outer housing that houses both the dial sleeve and the inner housing;
• wherein, said first rotational stop member is configured to prevent a user from selecting a dose greater than a pre-defined maximum selectable dose when said user rotates said dial sleeve to select a dose;
• wherein said first rotational stop member engages with said second rotational stop member of said dial sleeve when a user attempts to select a dose greater than said pre-defined maximum selectable dose and
• wherein said second rotational stop member comprises a flexible member that is separated from part of the dial sleeve by a cutting slit and is configured to pass over the first rotational stop when the dial sleeve is assembled over the inner housing.