BD20 Block Detector Module -- .01 to 20 Amps

01 to 20 amps. Detects presence of train in block by the current it draws in a range from 0.01 to 20 amps. No electrical connection to track, simply route track feeder wire through holes in tombstone current. Does not reduce track voltage or get hot. Easily connects to Auxiliary Input Unit (524-200, sold separately) or most signal systems.