Make your layout even more realistic with this bridge, equipped with lights that change from green to red to signify approaching trains of possible blocks. Lights change from green to red to warn approaching trains of occupied blocks ahead Compatible with both FasTrack and traditional tubular O and O27 track systems Use an insulated track section or a 153IR (both sold separately) PRODUCT SPECIFICATIONS Gauge: O Gauge Scale Type: Traditional Dimensions: 3 ?" x 4 ?" x 7 ?" Most Recent Catalog: 2016 Lionel Volume 2 Catalog