These bolts and nuts prevent the theft of items such as number plates. They can be fastened with a slotted driver in a clockwise motion, and the design prevents these fixings from turning in an anti-clockwise motion, therefore, keeping the screws fixed. They are suitable for use on most vehicles' license plates, as well as applications where either theft or vandalism is common and expected, such as wall-mounted safes and public toilet fittings. Please note this product is a deterrent and will not guarantee against theft.