Available in three sizes to fit any GROCO ARG Strainer, FLUSHcap makes flushing your raw water cooled equipment a snap. Temporarily replacing your existing strainer cap with a FLUSHcap will allow you to easily connect a Port-O-Flush Jr. or garden hose to your system. Use FLUSHcap to flush your 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.