Kato Unitrack (S124C) Straight Level Crossing Track 124mm N Gauge 20-027. This track allows you to create a realistic level crossing scene with its included alarm and circuit breaker. The single-track crossing kit features a 124mm long straight railroad crossing line. It's designed for single-track use and provides an inexpensive and easy way to enjoy the atmosphere of a real first-class level crossing. Compatible with the KATO unitrack system.