Culligan CULLIGAN-ISH-200 is an in-line shower filter that reduces chlorine, sulfur odor, and scale buildup in your shower water. It's easy to install and requires no tools. The filter cartridge lasts for up to 6 months or 10,000 gallons of water, and it's easy to replace. The Culligan CULLIGAN-ISH-200 is a great way to improve the quality of your shower water and enjoy softer, cleaner skin and hair.