Fade defy plug. 1st day fresh for 50 days (on low). Plug with low-level indicator light. Low Level Indicator: Febreze Warmer has a blue light that: Flashes twice when first plugged in to show it's working; Flashes continuously when it may be time for a new refill. Febreze Plug has two alternating scent chambers for noticeably long lasting freshness.