The Fluke Networks NFC-CARDS-5PK Fiber Optic Cleaning Cards come in a 5-Pack for easy cleaning. Includes: 5 cards with 12 sealed cleaning zones each - perfect for troubleshooting. Because the #1 cause of fiber optic cabling failures is due to contaminated end-faces, it is imperative that all optical fiber connections are clean and free of contaminants. Fluke Networks' Fiber Inspection & Cleaning Tools are the solution. Whatever your particular needs are, Fluke Networks provides you with the solution to ensure your fiber connections don't bring your network down.