A really clever new accessory from ARB is the tire pressure gauge with quick release function, which makes it easy to lower the air pressure for off-road use.

And that is how it works:
First, the brass attachment is placed on the valve and then the valve insert is unscrewed - this means that it cannot be lost. The desired tire pressure is now set using a slide valve. This is very precise because the tire pressure can be read on the pressure gauge. Then screw the valve insert back in and you're done!