Update Nov 2017. It is not intended to restock these as they are now available from Moonracker. See https://www.moonraker.eu/antennas/ham-amateur-radio-antennas#cat=678. Please mention that you saw this note on the AMSAT-UK shop when ordering!
This is the very well known, tried and tested, portable antenna from Arrow Antennas in the USA. With special permission from them, we are able to offer these antennas for sale on our web shop. The model number is 146/437-10 WBP.
This model is the version with a split boom (minimising length for transportation), and also includes a diplexer enabling satellite operation from a single hand held rig. Note that a max power of 10 watts is recommended when used portable. The antennas is supplied without a carrying case.
Further details, specification and a short video are available on the Arrow Antennas web site at http://www.arrowantennas.com/arrowii/146-437.html