Discountinkllc 4 HP 564 564XL Refillable ink Cartridges with chips for HP Deskjet 3520 3521 3522 Officejet 4620 Our Compatible inkjet cartridges are cost saving alternatives to OEM (genuine) ink cartridges. 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 ink cartridges are designed as a cost effective and economical way of replacing your OEM ink cartridges. These cartridges work exactly the same as OEM ink cartridges but when they run out of ink, just refill and re-use them. They come with auto-reset chips on them so they'll be ready to go after each refill. A great way to help the environment and it's easy on your wallet too. You'll never go back to single use cartridges again! Refillable cartridges must be used as a SET and cannot be used in conjunction with original cartridges!