Securextra 358 is extremely difficult to penetrate, with the small mesh aperture being effectively finger proof, and extremely difficult to attack using conventional hand tools.'358' comes from its measurements 3" x 0.5" x 8 gauge which equates to approx. 76.2mm x 12.7mm x 4mm in metric. Technical description of 358 fence panel:Mesh Pattern: 76.2mm (3") x 12.7mm (0.5") resistance welded at each intersectionHorizontal Wires: 4mm diameter at 12.7mm centresVertical Wires: 4mm diameter at 76.2mm centres.