Available in three sizes to fit any GROCO ARG Strainer, flush caps make flushing your raw water cooled equipment a snap. Temporarily replacing your existing strainer cap with a flush cap will allow you to easily connect a Port-O-Flush Jr.® or garden hose to your system. Use flush caps to flush you raw water cooled equipment with Barnacle Buster®, fresh water, or to aid in winterizing your system. NOTE: Not intended to replace your existing strainer cap, for flushing use only.