A medical device and more particularly a drug delivery pump has an hydraulic reservoir, a metering device, a displacement reservoir, a drug reservoir, and a drug infusion port all contained in a housing that can either be attached to or implanted into a patient. In a preferred embodiment, a customer sends an electronic correspondence to a company via email. The second layer and the third layer are included in a striped ridge, and the second layer is positioned at a skirt of the ridge.