Concertina Wire

Concertina razor wire has adjacent loops clipped in pairs at various points around the circumference of the razor wire. The clips force the roll to open in diamond shaped patterns, more like an accordion than a slinky, creating a much denser and more secure barrier. Concertina coils look to some like two rolls of razor wire intertwined. 

Concertina razor wire is formed in large coils which can be expanded like a concertina. Concertina razor wire is also called barrier concertina, concertina security barrier or concertina cross razor wire. This concertina style is often used to protect high value assets and to insure public safety.