The bottle is a wonderful asset. Close very easily and in "normal" upright transport. We use for the transport of water bottles in a rule, the outer pockets of the backpack. The large opening makes it easy filling and cleaning. Who wants to drink directly from the bottle, takes the "suction cover" who is using a cup or can drink too careful that he does not showered in the last sips on clothing, takes the screw. We have both shutters at home and use as needed the appropriate cover.