Where there are no buildings or indeed where access to the roof is not practical, there is a Robop trailer system. The Mark4 trailer launched in 2006 is a custom-engineered product with a pneumatic pole on top of which Robop sits. This puts Robop 22 feet above ground in the standard configuration or 30 feet with the optional taller pole. To reduce the weight aloft and extend the useful running time an option is available where the internal batteries are removed from the bird and the system is powered by an 80AHr leisure battery housed on the trailer chassis. This allows 4 months of continuous operation between charges. The trailer is light, very easy to move around and the pole takes less than a minute to erect. With a wheel base of 6 feet it fits the tramlines of ploughed fields when being pulled behind a tractor. Photos show the trailer system in use at Schiphol Airport near Amsterdam.