A medicament delivery device has proximal and distal ends; a medicament container with a plunger, a neck portion, and a delivery member unit; a housing extending along a longitudinal axis with proximal and distal open ends; a drive unit configured to apply a force on the plunger; and a C-shaped tubular body with a longitudinal slit/gap such that body can be attached to the neck portion forming a container unit. The C-shaped body also has an inner support configured to interact with the neck portion and with the delivery member unit and prevent the medicament container from moving relative to the body after the medicament container is attached to the body, and outer support configured to interact with a corresponding support of the housing to prevent the C-shaped tubular body from moving relative to the housing after the container is arranged within the housing through the distal open end.