Injection device comprising a tubular elongated main body, a needle shield slidably arranged in said main body, a needle shield link slidably connected to said needle shield, a enclosure containing medicament arranged in said main body, a needle connected to said enclosure, a plunger operatively arranged to said enclosure for ejecting said medicament through said needle and arranged on its upper part with a number of outwardly extending stop members, spring means arranged to said plunger for operating said plunger, a dose activating means, a needle shield spring surrounding the needle shield link. The invention is characterised in that said injection device further comprises a first tubular member rotationally and slidably arranged inside said needle shield link, said tubular member comprises a number or ridges and protrusions on both its outer and inner surfaces, said ridges and protrusions on the outer surface of the tubular member co-operate with guide members arranged on the inner surface of said needle shield link, said ridges and protrusions on the inner surface of the tubular member co-operate with the outwardly extending stop members of the plunger that said injection device further comprises a second tubular member arranged inside said housing, arranged and designed with a number of ridges and protrusions on its inner and outer surfaces capable of setting and delivering a certain preset dose.