Review on 🖨️ Cool Toner - Compatible Toner Cartridge Replacement for HP 78A CE278A - Laserjet 1536dnf MFP, P1606dn, M1536dnf, P1566, P1560 - Printer Ink (Black, 4-Pack) by Kyle Deel

. I bought them twice and all four don't seem to last as long as any of the original cartridges. My wife prints most of the time and this year alone I think she used 6-8 cartridges. I used to buy 3-4 year round with previous toner carts. I don't know why they put less toner in there, or maybe it's a different quality, but definitely not for that long.