Having driven unhappily behind a ready mix truck dribbling concrete from the chute, I completely understand the motivation behind the ConcreteSock. This simple and durable cover over the end of the chute, costing about £250, prevents concrete from falling out during the return trip. In England, Cornwall Ready-Mix Concrete has mandated the use of the ConcreteSock for its entire fleet. It has noticed a significant reduction in calls about chipped windshields and damaged paintwork. This device may be especially useful where washout facilities are limited, such as on environmentally sensitive sites, or city center locations. The ConcreteSock is not yet available in the U.S, although the UK firm behind it is seeking a partner, having already secured provisional U.S. patent protection. For further information, see www.concretesock.co.uk.