Transcutaneous analyte sensor

An analyte measuring system, comprising:

• a mounting unit adapted for mounting on a skin of a host;
• an electronics unit detachably connectable to the mounting unit, wherein the electronics unit comprises electronic circuitry encapsulated within a sensor body, and wherein the electronic circuitry is encapsulated in the sensor body by a molded water vapor permeable polymer material to provide a substantially seamless exterior with a portion of an electrode system exposed on the exterior of the substantially seamless body;
• and
• a sensor configured for measuring a level of an analyte, the sensor comprising an in vivo portion for insertion through the skin at an exit site of the host and an ex vivo portion connected to the mounting unit, wherein the sensor is operably connected to the electronics unit when the electronics unit is detachably connected to the mounting unit, and wherein the in vivo portion comprises the electrode system.