Membrane Solutions 20x4.5 Big Blue Water Softener Filter – Ion Exchange Resin, Whole House (1-6 Pack Options)

This is a Membrane Solutions water softener filter cartridge, sized 20 inches by 4.5 inches—fits standard big blue housings.

It uses ion exchange resin to yank out calcium, magnesium, iron, and lead, so it's great for hard water.

Rated for up to 150,000 gallons, and you'll wanna swap it every 8 to 12 months depending on your water.

Model is IFRES002_M, and it's blue.

Works for both household and commercial setups.

New in original packaging, and you can buy 1 to 6 packs depending on how many you need.

Comes with a 1-year warranty.

If you've got scale buildup or just want softer water throughout the house, this is a solid pick.