Universal Charcoal Pre-filter Compare to Honeywell Part # 38002 (Hrf-ap1)
This filter is larger than it needs to be for your machine in order to fit most portable air purifier models. It takes less than five minutes to change; just trim the filter with scissors to match your existing pre-filter size. Lower cost replacement for part #38002 and #30901 For best results, change pre-filter every 1 to 3 months