The Mini well L630 Personal Camping Purification Water Filter Straw is a portable water filter straw that you can use to purify water from any source. It's lightweight and small, so it won't take up much space in your pack. It's perfect for emergency preparedness or survival situations as well as everyday use for hiking, backpacking, camping, or traveling. Our gravity water filter straw features a one-touch design with an auto shut-off function that allows you to drink without having to turn the filter on or off again after each sip. It also includes a flip cap cover over the mouthpiece to protect against dirt and debris when not in use. Our water filter straw is made of BPA-free plastic and comes with two interchangeable filters: one pre-filter and one carbon block filter. The pre-filter helps remove larger particles like sand and mud before they reach the carbon block filter, where they are removed completely from the water supply by adsorption (a process in which molecules adhere to surfaces). This process removes 99% of harmful bacteria from contaminated drinking water sources like lakes, streams, rivers, ponds, and puddles.