Dual opening design - slider sealed wide opening and standard 42mm neck Attaches to filters with a 42 mm thread, such as the Katadyn BeFree (NOTE: The product is not compatable with the Sawyer Squeeze or other 28mm thread filters) Easy to fill and simple to clean and dry due to the wide opening Lightweight and compact at only 3.1 oz Durable- despite the soft material, the Vecto has a breaking point of 220 lbs