A Little Bit Goes A Long Way
Here are cartridges for delta faucets. There are slight differences in quality; The plastic one is standard and comes in most faucets. The middle one with brass a stem is decent quality and has the same seat as the plastic one. The highest quality piece has a ceramic seat and ceramic base, as well as a brass stem. Day and Night suggests you go with the highest quality. It is absolutely a worthwhile investment. It takes more punishment and will outlast the others by far. A little bit really does go a long way in this instance.