2pcs Replacement Filter for Philips Air Humidifier HU4801 HU4802 HU4803 HU4811 | eBay
Amazon.com - WuYan 2pcs Black Replacement Filters for Philips HU4102 Humidifier Wick Replacement Filters,Compatible with HU4801 HU4802 HU4803 Humidifier Parts
How to Replace Filter on PHILIPS Air Humidifier HU4803/01 - PHILIPS Air Humidifier Maintenance - YouTube