Discountinkllc - 4 HP 940 940XL Refillable ink Cartridges + new Chips for HP OfficeJet Pro 8000 8500 8500a Printer 940 Black Cyan Magenta Yellow Non-OEM Refillable Ink Cartridge Set, There are easy-refill hole and rubber plug on the top of each cartridge. Ink Type: Dye Based Ink, UV Resistant, High Quality Material Sold and ship by Discountinkllc backed 1 Year Manufactured Warranty. Refillable cartridges must be used as a SET and cannot be used in conjunction with original cartridges!