For use in ET-8500 & ET-8550 100% Satisfaction & Lifetime Guarantee Photo black has its own designated slot in your machine and should print in conjunction with your other five ink bottles in this series. T552020 black and T552120 photo black are not interchangeable. Page Yield: 7300 Shelf Life: 18-24 Months The use of compatible replacement ink bottles and supplies does not void your printer's warranty.