Convatec 416409 Natura+ Filter Closed End Bag, Opaque, Standard, 57mm, Product Details Natura+ Filter Closed End Bag, Opaque, Standard, 57mm, 2 1/4" Natura+ Bags They are designed for single use only. They are available with a filter that is designed to reduce odor and gas buildup. There is no cumbersome or drain clip to worry about. When you're done, simply remove bag, place in disposable bag, then discard Size: 57mm, 2 1/4" with opaque standard filter 30/pk