Hollister CenterPointLock - 7 1/2" 2-Piece Closed Ostomy Pouch with Filter is made up of four layers to prevent odors from escaping the ostomy bag and minimize pouch noise. The built-in filter contains carbon, which deodorizes gas before it escapes the pouch. This filter also prevents the pouch from ballooning and increases discretion. The CenterPointLock system provides a secure hold between your pouch and the ostomy wafer to keep the two pieces from separating accidentally. This Hollister pouch has built-in belt tabs and can be worn while swimming or bathing.