MSR Guardian Water Purifier Pump - Portable Water Filter System for Backpacking, Camping, Hiking, Emergency Preparedness & Global Travel - Removes Bacteria, Protozoa & Viruses from Lakes, Rivers & Streams

This MSR Guardian is not the smallest or lightest purifier, but it does a great job at what it is supposed to do. It takes a short amount of time to pump the purified water in a bottle. Even better is if your bottle or container has a wide mouth that can be screwed on to the device. Otherwise, you play a balancing act pumping and holding the container for the water so that is will not spill out.Doesn't need a deep water source to be able to pump. Really like how it backflushes to keep it clean. You do want to make sure you keep this maintained over the years, especially if you do not use it all the time. It will keep some water in the device and you do not want it to dry out. There is a maintenance kit available to keep other working parts moving smoothly.It is very pricy, but it does a great job. It really makes the water taste great, and you have the peace of mind that you are getting clean water. While it is heavy for backpacking, I think the weight is worth it. I am very happy with it.