AquaC EV-120 Protein Skimmer Flexible design for in-sump or external applications The new EV Series skimmers are designed to run in sumps WITHOUT BEING RAISED. The output gate valve The addition of a precision ball valve for airflow control allows the aquarist to fine tune the skim The John Guest "Speedfit" fitting is a great feature you will only find on AquaC ozone-equipped skim The improved "Twist-Lock" collection cup and cap makes for a secure, flanged connection without the