simpure 5 micron 20" x 4.5" gac granular carbon whole house water filter | reduces chlorine, replacement filter for 20-in blue big housing db20p, db20p-3, whb20, gac-20bb, rfc20-bb. 2 pack is up for auction in Home & Kitchen. The current bid is $1.00, in Good Condition. This auction has ended — similar items appear in live auctions regularly.