Discountinkllc HP 920 Refillable ink Cartridges with chips for HP OfficeJet 7000 7500 7500A Printer 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 Refillable Cartridges with Auto Reset Chips (ARC). You do not need to reset the cartridges manually. All you have to do is remove the rubber plug on the top of the cart, inject ink until full, put the rubber plug back in place, and you are ready to go. 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!