Only original Brother LC21BK Ink Cartridges can deliver optimum performance from your Brother printers, fax machines and all-in-ones
Unlike bargain inks, original Brother LC21BK Ink Cartridges are products of a deep commitment to research and development which produces blacker blacks
Own my own business and print lots of forms the Brother's ink is very good and lasts awhile. Easy to instal. I like the heads up when ink is low so I can plan a purchase.
Can't say if it has longevity. Just got it. Staples was great about getting it for me. The numbers for the cartridges have changed since I bought my Brother MFC3100-C. Lucky for me someone knew which one I needed.