The CAT24C64HU4I-GT3 is an EEPROM (electrically erasable programmable read-only memory) manufactured by ON Semiconductor. It is a 64KB I2C SER EEPROM MUX (multiplexed) device, meaning it can be used to multiplex up to eight I2C bus transactions onto one device. This device contains 8 KB segments, allowing 8 addressable I2C memory pages with self-timed write cycles of up to 5 ms. It also features low power consumption and fast write times. The CAT24C64HU4I-GT3 is suitable for use in memory expanders, memory changes, or data logging applications. It is designed to operate from a wide voltage range (1.65V - 5.5V), making it a versatile memory solution.