Child restraint system for an infant

A child restraint system for securely carrying an infant in a vehicle, said child restraint system comprising a rigid shell that is concave of an inner side and which may be attached to a seat of a vehicle, to provide a unitary element that serves as both seat and back for supporting the infant, and a harness for holding the infant within the concave side of the shell; the unitary element comprising two parts that are hinged together so that the shell folds along a center line running through the rigid shell, each part comprising at least two panels, such that each panel is attachable to adjacent panels to form the rigid shell, or disconnectable from the adjacent panels so that the child restraint system is compactable into a substantially flattened configuration for storage.