Product Features: This dog toilet system features a two-layer structure with an antibacterial dry filter and a highly absorbent/odor-eliminating mat, allowing for no-odor use for up to 3 days without changing. The mat only needs to be changed once every 3 days, and the filter once a week. *For regular size, this is based on a single dog (under 4kg) urinating. Please remove feces promptly.