You have seen them on trucks and now you purchase them for your Caravan. Fits all Alko or BPW standard bolts.
They are especially designed for Alloy Wheels and have a unique registered design to enable you to see immediately if your wheelbolts become loose.
Whenever your vehicle is serviced, it is important that you follow the manufactures instructions and re-torque the wheels nut/bolts periodically, in strict accordance with the manufactures instructions before fitting the wheelbolt indicators.
Periodically check your wheels to ensure there has been no movement of the wheelbolt which is easily shown by the directional arrow on the wheelbolt indicator.