This citrus zest refill for rubbermaids tcell 20 odour control system delivers a consistent level of lemony fresh fragrance for 30 45 days as the tcell 20 operates discreetly with no noise or moving parts your guests are only likely to notice the pleasant smell and nothing else the refill also contains microtrans technology which neutralizes odours instead of masking them making your washrooms smell clean and fresh without leaving behind an overpowering scent tcell refill citrus zest