GRM172 Series Plastic Filter Kit for 172mm fans Guard & Snap-in Retainer Plastic - reinforced ABS, UL approved materials Rating UL94V-O Media Polyurethane foam material meets UL94HF-1 or higher. UL approved Rating UL94HF-1. Porous mesh 30PPI, 45PPI or 60 PPI available PPI = Pores Per Inch. Snap-in Retainer makes cleaning or replacing media simple. No tools required.* Low air resistance, filtration of particulate matter, noise abatement Part Number Description GRM172-30 172mm Fan filter kit, includes G172P guard, R172P, retainer, and 30 ppi media GRM172-45 172mm Fan filter kit, includes G172P guard, R172P retainer, and 45 ppi media GRM172-30/PK 10-Pack GRM172-30 filter kits, Boxed GRM172-45/PK 10-Pack GRM172-45 filter kits, Boxed 10557 Metric Drive Dallas, Texas 75243 214-340-0265 OrionFans.com RoHS Compliant Information and data is subject to change without prior notification. Mouser Electronics Authorized Distributor Click to View Pricing, Inventory, Delivery & Lifecycle Information: Orion Fans: GRM172-45