QFX-SFP-1GE-T Juniper SFP Mini-GBIC Transceiver Module Rj-45

The physical layer IC (PHY) can be accessed via I2C, allowing access to all PHY settings and features. The 1000Base-T has an input voltage range of 3.3 V +/- 5%. The 4 V maximum voltage is not allowed for continuous operation.