To build a complete mounting solution for an Aqua Box you will require an AMPS base (RAM-B-202) which screws into the underside of the holder, a double socket arm and a surface base (clamp / suction / screw etc.). These components can be found in the Compatible Parts list above and more here.
* For maximum rigidity (e.g. off road bike use) consider the larger 1.5" diameter C Series ball & socket system which will require the larger AMPS base (RAM-202) which screws into the underside of the holder together with an appropriate double socket arm and surface base. C Series components including arms and bases can be found here.