Compatible Inkjet Cartridge with Neopost #4105243U/ 4139518X / IJINK3456H. Filled with UV Red Ink, USPS approved. Yields up to 17,000 Impressions. All of our cartridges come with a 6 month guarantee against defects, no other dealer will stand behind their cartridges like this... This cartridge fits the IJ35, IJ40, IJ45, IJ50, and IJ60. Plus if you send in you empty cartridge, you get a $10 credit applied back to your credit card, up to 2 cartridges can be sent in for this credit, all must be "Virgin" never been refilled before. Any other cartridges will not qualify for this rebate.