Flexible implantable subcutaneous heart device (HD) structure, including a flexible device body, at least one flexible lead and at least one respective transition unit, the transition unit for respectively coupling each flexible lead to the flexible device body, the flexible device body including a plurality of inner components and a respective plurality of hollow outer units, the hollow outer units for encasing and protecting the inner components, each one of the hollow outer units including at least one hollow rigid element and a hollow flexible element, the hollow flexible element coupled with the hollow rigid element for enabling the outer unit a degree of flexibility, wherein the hollow flexible element is covered with a covering and wherein the flexible device body is covered with a polymer.