ALPHA MIMIC 12x Red/Green Ground Signal _ A pack of 12 x 2-lamp plug and play signals in 4mm scale (OO) complete with control board and accessories. The DCD-MGS-RG is a simple design 2-lamp ground signal that was first seen on a limited basis in the 1920 in the UK but it was very widely used internationally. In addition to its world-wide use it is also perhaps the perfect indicator signal for those with large storage or fiddle yards giving a clear Red/Green indication of track access if used for this.