Sur-Fit Natura Urostomy Pouch. The plastic coupling ring allows the pouch and skin barrier to snap together for audible security. The anti-reflux valve prevents urine from returning to the top of the pouch around the stoma and the comfort panel is designed to be quiet and odor-proof to help maintain discretion. Standard: 10" opaque pouch with 1-sided comfort panel and Accuseal Tap with Valve. 2-1/4" flange, 10/box.