Absorbs odours. Keeps your fridge fresh so food tastes better. Also absorbs ethylene gas and moisture which helps keep fruits and veggies fresh longer. Made from natural activated charcoal. For extra-large refrigerators use two packets. Each 50g packet is effective up to 30 days and can be placed in the sun for 3-4 hours per side to recharge. Packet can be used up to 6 months before replacing. Also absorbs up to 10% of its own weight in moisture reducing condensation. And absorbs xylene, formaldehyde, benzene, ammonia, tvoc, toluol, and methanethiol.