Hornby R638 Roll of Track Underlay A resilient foam underlay that fits under track to simulate a full-size ballast track bed. It also damps out vibrations so trains run more quietly and there is less chance of'wheel bounce' to spoil performance. Approx 4880mm long, this strip is the width of single track with indentations for fit the sleepers. The strip if flexible to follow any straight or curved track, and is easily cut to make junctions at points and cross-overs. Brand new item direct from our new Yorkshire shop.