Jabsco Vented Loop 3/4". These Pump Parts & Accessories by Jabsco are recommended for use with manual and electric marine toilets installed below the waterline (static or heeled). The Jabsco Anti-Siphon Device prevents back siphoning and odors from your marine toilet. For most toilets a vented loop is sufficient; however if your toilet lacks back pressure a vented loop may be necessary. A self-venting loop is highly recommended. The Jabsco Vented Loop is self-cleaning; however a plunger with a sleeve should be installed at the same time. When a plunger is installed back-flushing the toilet should be turned off. An anti-siphon device prevents back-siphoning; however it must be installed at the same time as the backflushing procedure. A vented loop should not be installed if backflushing is not an option. Backflushing should only be attempted when the toilet is removed from the pump. Specifications for Jabsco 3/4" Vented Loop: Manufacturer: Jabsco Color: Black Package Contents: Jabsco 3/4" Vented Loop Jabsco 29015-0000: Vented Loop 3/4"