Features: -Set of 2 refills -Biodegradable -Very economical -Powder scented for odors -Indicator on recharge showing that the end is approaching -Each refill holds up to 990 layers BIODEGRADABLE REFILLSDékor refills are also available in a biodegradable formula that helps them to break down quicker than ordinary refills. As defined (ASTM 1991), "A Biodegradeable Plastic is defined as a degradable plastic in which the degradation results from the action of naturally occurring microorganisms such as bacteria, fungi, and algae."