An infusion device including a site and a set for delivery of a substance to a patient. The site can include a cannula that is introduced into a subcutaneous layer of skin of the patient. The set can be coupled to the site by placing the set over the site and moving the set from an unlocked to a locked position. The set can be oriented at multiple rotational orientations with respect to the site, and can be coupled and uncoupled with the site multiple times. Also included is a device for inserting a subcutaneous infusion device into a subcutaneous layer of skin of a patient. Some devices automatically retract a needle used to introduce the cannula. Upon full introduction of the needle and associated cannula of the subcutaneous infusion device into a subcutaneous layer of skin of a patient, the device can move the needle into a retracted state.