CoreCarbon Prefilter Overview This high-quality replacement pre-filter is designed to fit Honeywellx Insight Air Purifier Models HPA5100, HPA5100W, HPA5100B. Our finely ground, powdered, coconut shell, activated carbon media provides superior surface area for adsorption of VOC's and other odorous gases (Minimum of 60Percent CTC). Powdered carbon provides faster adsorption than granular carbon and is cleaner to handle during replacement pad changes. Each microporous activated carbon replacement pad provides the adsorption surface area of over 10 tennis courts.Replaces: CoreCarbon Pre-Filter replacement for inchCut-to-Sizeinch HRF-AP1 and HRF-APP1 (Labeled as 'Ainch or 'A+inch). CoreCarbon Pre-Filter replacement for inchPre-Cutinch HRF-A100 (Labeled as 'Ainch or 'A+inch). Specifications: Pre-filter size: 7-3/8inch x 10-1/2inch Nominal thickness: .200inch Material: High Grade Powdered Activated Carbon Quantity: 4 Pre-Filters – Exact FitmentxRegistered mark of air purifier manufacturer. The products advertised on this page are manufactured by CoreCarbon.