Topeak have made a precision presta valve extender for deep rim applications. Making sure you can pump up when you need to.
. Material: Machined Aircraft Aluminium ALloy
. Size (LxWxH): 4.3x0.7x0.7cm / 1.7x0.28x0.28inches
. Weight: 3.4g / 0.12oz
. Colour: Black