4 quart ND &trade; pigment bulk refill ink for HP 940 940XL Pro8000 Pro8500 Pro8500A and HP 950 950XL 951 951XL OfficeJet Pro 8100 Pro 8600 printer.The item with ND logo. ATTENTION! We don't have refill instructions for this printer at this moment.. Smell:Slightly ammonia odor Stability:No settling in 2 years (at normal storage) Lightfastness:7-8 BWS Temperature:-12 C no frozen, 50 C no gelling Particles:&lt; 0.5 micron (Average &lt; 100 nanometer)