Fluid Pumping Unit (FPU): The FPU is contained within a Nomex cloth pouch for ease in storage and transport. It is composed of the pump/motor, piping, sensors, and supporting structure required to pump water through the IRU system. The FPU's positive displacement pump contains an integral motor designed for continuous operation. A motor drive control governs pump speed by regulating the motor input voltage. A current limiting device is also provided. Power is not required when filling the system but is required at the RAHF when transferring water to the water tank and when disposing of excess water. Two counters are provided that mechanically indicate the number of liters of water pumped (resettable) and total liters pumped (not resettable).

Collapsible Water Reservoir (CWR): The CWR, also contained within a Nomex cloth, is a flexible, stowable bag, which contains the water for transfer. The main body is constructed of two layers. The inner bladder is made from a polyether polyurethane material compatible with potable water and the outer bladder is made of a Kevlar reinforced urethane to provide pressure holding capability and to provide protection against accidental cuts and tears. A panel of urethane is attached to both sides of the CWR to limit its expanded height. A thermoplastic hose with a quick disconnect mates with the FPU.

Hose/Adapter Accessories: An adapter is provided to enable the dumping of excess water into the orbiter Waste Collection System with a quick disconnect at the IRU end and a twist lock connection to the waste system.