- Odor control: activated-charcoal filters absorb odors from composting bins, helping your kitchen stay fresh and clean. - Flexible coverage: includes round and square filters. Using both shapes provides better odor absorption, and the square filter fits round lids because the rim holds it in place. - Easy to install: simply push replacement filters into the compost bin lid for quick setup. - Material and care: made of activated charcoal; do not rinse for best performance. - Size and compatibility: square filters 4.75 inches on each side; round filters 6.75 inches in diameter. Compatible with most stainless steel compost pails. Can be cut to fit non-standard sizes or shapes as needed. - Use scenarios: - Home kitchen: keeps a countertop compost pail smelling fresh. - Round or square lids: the square filter works in round lids due to lid rim support. - Small office or non-standard pails: trim filters to fit various sizes for effective odor control.