The injection device has an axially movable piston rod that is mounted in a housing (105) and is moved by a conveyor for dispensing fluid. A receptacle is mounted in housing to receive fluid product. A dosing device is detachably connected with the conveyor through a coupling mechanism (110) to dispensing fluid. The teeth-bearing coupling surfaces are formed in the coupling mechanism to produce acoustic or tactile signals corresponding to adjusted or corrected dose of the product during dose dispensing process or dose correction process.