you cant kill centrists if the bioposadists get you first Uh if you live in eastern Europe, pmk series or gp7v series they usually go for around 20-30 dollars and have a voice diaphragm drinking tube, if you live in a nato country id reccomend the isreali 4a1 for serious use, its got a drinking tube, no diaphragm but its only like 30 bucks for a full carry bag filter kit, and the 40mm nato filters are incredibly cheap in nato countries, like 5-15