Typically used to protect military installations, concertina differs from barbed wire as it has a double spiral and very sharp razor blades as opposed to pointed barbs. Supplied in individual rolls in a cardboard box, once opened creates a 60 cm (approx.) spiral spring effect (28 spirals) stretching out to a length of 8 – 10 metres. Heavy galvanized (275 grams/zinc per sq metre) core wire 2.5 mm diameter, razor blade 0.5 mm , breaking strain 785 kg. Concertina wire is a true intruder deterrent and quicker to install than traditional barbed wire.
