This cartridge uses 100% KDF-55 patented filtration media. KDF is much more effective on hot water than carbon media which can dump contaminants at high temperatures.
KDF media has been in use for over 15 years. It is an NSF certified material and it is the most effective media for use in a shower head water filter.
This cartridge has a useful life of between 6-9 months in most cases. The useful life can vary based on how many people use the shower, how often, & for how long, as well as your local water conditions. Your cartridge could get more or less life depending on these factors.