Stupid question maybe but can you explain why you would use EK-RES X3 - Internal Tube 12/16 40mm
From OC page
EK-RES X3 - Internal Tube 12/16 40mm is an upgrade tube for EK-RES X3 - Multiport TOP which further expands the use of EK-RES X3 series reservoirs. These tubes, which are sealed with quality NBR rubber gasket, allow the ports on EK-RES X3 - Multiport TOP to be used as an outlet (suction) ports as well.
I just want to understand what this tube does
From OC page
EK-RES X3 - Internal Tube 12/16 40mm is an upgrade tube for EK-RES X3 - Multiport TOP which further expands the use of EK-RES X3 series reservoirs. These tubes, which are sealed with quality NBR rubber gasket, allow the ports on EK-RES X3 - Multiport TOP to be used as an outlet (suction) ports as well.
I just want to understand what this tube does