117—Mechanical signalling devices
(1) A mechanical signalling device must—
(a) be fitted to the right side of the vehicle; and
(b) be able to be operated by the driver from a normal driving position; and
(c) consist of a white or yellow representation of an open human hand at least 15 centimetres long; and
(d) be constructed so that the driver of the vehicle can keep the device—
(i) in a neutral position so it is unlikely that the driver of another vehicle or anyone else would regard it as a signal; and
(ii) in a horizontal position with the palm of the hand facing forwards and the fingers pointing out at a right angle to the vehicle to signal an intention to turn or move right; and
(iii) with the palm of the hand facing forwards and the fingers pointing upwards to signal an intention to stop or reduce speed suddenly.
(2) When the mechanical signalling device is in a position mentioned in subrule (1)(d)(ii) or (iii), the complete hand must be clearly visible from both the front and the rear of the vehicle, at a distance of 30 metres.