3M Multi Gas Vapor Cartridge, Filter 60926, P100 Respiratory Protection, 2 Sets of 2

I've used these for years. If you're not using the mask frequently, buy some big ziplock bags and put the whole mask in the bag when you aren't using them. Just double check that the cartridge is what you need for the chemicals you are exposing yourself to. The p100 spec is in reference to the particulates. Also these cartridges are not a substitute for a situation where you need a fresh air supplied mask. Stay safe.