1: Working(safe) pressure range is from 3mpa to 12 mpa(About 450psi to 1800psi), NOT Constant Pressure Valve. Suits low requirement players.
2: The top hat size is 3.2 / 8mm, if you need other size, please contact me.
3: Player suggestions: 4.0mm inner hole - 4.5mm(.177 cal) barrel; 4.5mm inner hole - 5.0mm(.20 cal) and 5.5mm(.22 cal) barrel; 5.5mm inner hole - 6.35mm(.25 cal) and 7.62mm(.30 cal) barrel.
4: We have factory, if you need lots of valve and want to use your logo, please contact us.