I use a 7880 and this is my first use of your product. I ordered the full replacement pkg last July. The packing sheet Product ID isCCP-7880-220-KIT, order ID is S0307466348. When I went to replace the empty Lt Black OEM cart with the Cone cart, I noticed that the OEM Light Black cartridge needing replacement was a T6037 but the Cone replacement is T6047. After scouring the internet inconclusively, I decided to try filling & inserting the new Cone cart anyway and then found that the Cone cartridge cartridge wouldn’t fit into the printer. Comparing it with the OEM cart, the Cone cart is about 2.75 in longer. I must have ordered wrong, or you maybe have sent the wrong carts for my 7880. Also, no O-rings were included in the shipment. What can we do at this point? I’m re-inserting the empty OEM cartridge and suspending printing until this is resolved.