This invention relates to an injection site or gateway or a system comprising such an injection site or gateway. In one form the invention concerns a system comprising an inserter device and a gateway for subcutaneous injection of fluid where comprises a distal surface (1a) corresponding to a proximal surface (1b) integrated with the inserter device. In another form the invention concerns a gateway for subcutaneous injection of fluid, which gateway comprises —a body (1) with at least one through-going opening (6) with an entrance and an outlet, and at least one cannula (3) and having a proximal end protruding from the lower side of the body; —and at the entrance of the through-going opening medication can be injected by a delivery device (20) which delivery device has protruding parts (22) which form an inner opening with a diameter di; wherein the surface of the entrance is shaped in such a way that the cross-section of the top part of entrance, i.e. from the top of the entrance to a position di/3 below the top, do not exceed di.