nine ball neo r hojtryksventil umarex glockNine Ball (Laylax) has made a really smart NEO R high pressure valve. This valve gives your gun magazine better muzzle velocity and more consistent shots. It comes fully open as standard because the valve here can be adjusted so that you can have it fully open, half open and almost closed When it is almost closed you get a lower exit velocity and use less gas per shot. This fits the following Umarex Glocks: Glock 17 Glock 18C Glock 19 Glock 19X Glock