Replaces Honeywell HRF-R1 and HRF-AP1 Recommended to replace every twelve (12) months, or more often in harsh environments, for maximum efficiency PreFitler: Recommended to replace every three (3) months, or more often in harsh environments, for maximum efficiency PreFitler: Recommended to replace every three (3) months, or more often in harsh environments, for maximum efficiency Pre-Filter: Recommended to replace every three (3) months, or more often in harsh environments, for maximum efficiency Approximate Dimensions: 6 1/2 x 10 1/4 x 1 1/2 inches PreFilter: Approximate Dimensions: 15 1/2 x 47 x 1/8 inches What You Get: Two (2) replacement filters AND One (1) replacement universal pre-filter Filter-Monster branded replacement for Honeywell A+R (HRF-ARVP) Filter Value Pack. One to two year supply of filters, depending on Honeywell air purifier model. **PreFilter is a Universal fit, makes 1-8 pre-filters depending on the size of air purifier