Convatec Natura+ Drainable Transp Pouch With Filter & Invisiclose 45mm (416416) 10s The Natura® + pouches are compatible with SUR-FIT Natura® Two-Piece Ostomy System which is ConvaTec’s most extensive two-piece product line. The Natura® + Flange System signals a secure, accurate closure with a series of audible “clicks”. A simple snap-off, snap on design allows users to change the pouch quickly to match activities without removing the skin barrier from the skin.