A valve operating device includes a mounting for attachment to a vehicle and an elongate arm, the free end of which is only moveable across the underlying ground. A preferred method involves spray coating a polycationic material onto a core lens, rinsing and drying the lens, followed by spray coating a polyanionic material, rinsing and drying. The download control bit has a priority state indicating that a message has already passed the target bus interface at least once without being downloaded. The cutting face of the delayering probe tip is configured so that each peeling step peels away an area of material having a linear dimension substantially equal to the linear dimension of the delayering probe tip cutting face. The orientation of the fine particles in the polymer medium can be carried out on a scale where required manipulations can be done with ease.