3M Aqua-Pure Whole house Replacement Cartridge Scale Removal AP917HD-S. Whole house replacement filter cartridge for AP904 filter system. Why Shop with US? Customer Service is our #1 Priority. If there is an issue with your order, please understand we are human and we do make mistakes. All carriers have daily pickups, these pickups are by the truckload and individual packages do not receive an arrival scan. Please understand this is out of our control. This item is in the category “Home & Garden\Kitchen, Dining & Bar\Small Kitchen Appliances\Water Purification\Water Filters”. The seller is “bistatebusiness” and is located in this country: US.