The Cnoc 2 litre bladder is made of extra durable TPU with a wide mouth opening for quick and easy filling. This squeeze water filter removes 99.99999% of bacteria such as Salmonella, Cholera, and E. coli, 99.9999% of protozoa including Giardia and Cryptosporidium, and 100% of microplastics, providing safe, clean drinking water from lakes, rivers, streams, and faucets worldwide.