The Rockshox Shock Pump is a must for anyone with Air sprung suspension.
It'll allow you to adjust your suspension pressures, to get the most out of your bike.
The hose swivels a full 360 degrees which helps it get into those hard to reach shocks.
The pump is capable of reaching pressures of up to 300psi. If you're running a shock that runs more pressure than that, then check out the Rockshox 600psi Shock Pump
There is a bleed valve on the side to allow you to drop pressure out too.