Device performance will be primarily evaluated in terms of the proportion of G4 System values that are within ±20% of YSI reference value for glucose levels >80 mg/dL and ±20 mg/dL at meter glucose levels <80 mg/dL. These G4-YSI matched pairs will be collected during in-clinic sessions on Days 1, 4, and 7 of Sensor wear. The proportion of matched pairs from this study (PTL-900360) meeting the above criteria will be compared to the proportion of such points observed in the DexCom clinical study that supported approval of the SEVEN PLUS System (PTL 300012).