A concertina coil, also known as a razor a type of fencing made up of multiple coils of sharp-edged metal blades that are arranged in a concertina pattern. The blades are designed to overlap and create a formidable barrier that is difficult to climb or penetrate. Concertina coils are commonly used in high-security areas such as prisons, military bases, and government buildings, but can also be used for decorative purposes in landscaping and architecture. The lly made from high-tensile steel and can be coated with different materials to create a range of colors and finishes. Installation requires specialized equipment and training to ensure proper tensioning and secure fastening. Overall, the concertina coil is a versatile and effective option for securing a variety of different areas.