Hudson RCI Water Trap This water trap or condensation trap is a simple device of durable construction to withstand the rigors of long-term daily use. Serving as a condensation filter, this device traps condensation in oxygen tubing before it reaches the oxygen therapy patient. The clear body allows easy visual inspection for fluid build up and assessment of cleaning or replacement. Tapered end-cap fittings provide for easy attachment to oxygen tubing. The Hudson RCI Water Trap is a cost effective solution for long term oxygen therapy patients.