LifeStraw Peak Series Personal Straw Water Filter - Can also be attached to water bottles and to standard gravity hoses with removable threaded bottom cap. Unlimited shelf life means no need to worry about how long ita (TM)s been in your emergency go-bag unused. Enhanced microfilter performance helps to reduce clogging from sand and silta -for better flow rate. Ultralight and durable, pack it anywhere for your backup hydration, emergency, or on-the-go needs.