This is the device that uses ionization technology to purify the air inside a refrigerator and activated oxygen to sanitize food. When placed anywhere inside a refrigerator, its negatively charged ions break down harmful airborne particles, extending the life of food and eliminating odors. It also sanitizes meat, fruits, vegetables, and surfaces using activated oxygen while reducing pesticide residue. Charges via USB; a four-hour charge purifies a fridge for up to 24 days. Purifies up to 17 3/4' cu. 3 1/2" H x 3" W x 3" L. (4 oz.)