POUCH, OST SENSURA MAXI 1PC 7/8" (10/BX) Anti-reflux valve prevents the urine from washing over the stoma. Soft tuck-away outlet is easy to use and can be tucked away when not in use. Multi-chambers spreads the urine evenly within the pouch resulting in a flat quiet pouch. Two layer protection: The protection layer protects the skin from stoma output and the skin care layer absorbs excess moisture.