Airgap AG100-003 Universal Triple Air Gap for Water Filters with Three 3/8-inch OD PortsAirgap AG100 003 The AG100 003 Universal Triple Air Gap is designed to provide an effective way of connecting water filters to a drain line. The paramount priority of this air gap is to protect the water supply. The AG100 003 easily connects iron filters, reverse osmosis filters, or boilers purge lines to a standpipe through a code compliant airgap. It also can be used for condensate drainage from air conditions, or sump pumps. The AG100 003 air gap