Does anyone knows weither the TFO Gatekeeper water filter http://www.flexi-flask.com/filtration.php4 fits on a platypus resevoir or not ?

and i also wanted to ask weither a Water Purifying Straw would be better or worse compaired with the Gatekeeper filter.

late me reformulate my quention: Does anyone knows weither the TFO Gatekeeper water filter http://www.flexi-flask.com/filtration.php4 fits on a platypus resevoir or not ? and weither a Water Purifying Straw would be better or worse compaired with the Gatekeeper filter for a EDC emergency water filter/purifator, since the gatekeeper is a FILTERS and a Water Purifying Straw purifises, but with a much lower Capacity. <br>