Page Yield*: 8,000 per cartridge For best results, store in a cool, dry place. Use within 36 months of purchase for optimal performance. *at 5% coverage (ISO/IEC standard) Our compatible postal meter red ink cartridges all exceed USPS requirements for fluorescence Compatible with the following Pitney Bowes Personal Post Meters: DM300C, DM400C, DM450C, 3C00, 4C00 and 5C00 Color: Flourescent Red Please contact us first with any product issues. We want all of our customers to be happy because happiness matters.