With Proto-Sound 3

9cm from centerline of track under the tower

Trainz Product Id: 11489812

This is an easy to build Model Power 411 Interstate Freight Terminal Kit

Circuitron 5501 BD-1 Opto-Electronic Block Occupancy Detector ProductID_11544248 With Proto-Sound 3This is Circuitron 5501 HO Block OCC detector w 2csd. BD 1 optical detector. Opto electronic block occupancy detector. Tiny Opto Sensors detect train movement. Sensors mount between the rails and activate circuitry when shaded from a passing train. Independent of track power, rolling stock requires no modifications. Sensors fit between ties and may be ballasted over in most cases. Circuitry is extremely sensitive and will operate properly under very