Defence Standard (Def. 61-12 Pt 6. Supplied on 100m reels. © Electrics for Model Rail layouts. Wire (7 x 0.2mm) 100m Black. Wire (7 x 0.2mm) 100m Blue. Wire (24 x 0.2mm) 100m Brown. Core: Stranded, 24 x 0.2 mm tinned copper conductor. ).