Check the listing for details. Circuitron 800-5201 DT-1 Grade Crossing Detector. Condition: New. Listed at 41.99 USD. CTRN800-5201 Specifically designed for use at grade crossings, using Opto-Sensors to detect the train. Output controls flasher, gates, bells, etc. Detects train when an Opto-Sensor is covered. Senses track polarity and activates only the Opto-Sensors for the direction of travel. Always turns off after the last piece of rolling stock clears the crossing. Includes four Opto-Sensors. Requires an Alternating Flasher Unit to operate flashing lamps. Note: DT-1 cannot detect a short train or loco if it falls between Opto-Sensors. Use in any scale with DC track power. 2 x 3" printed circuit board. All Scales with DC Track Power Bi-Directional 10-18 volt DC input Please be advised all our listings have a 2 day shipping and handling. Most of the times we are able to ship them the next day, but as a norm allow 2 days to see a tracking number in your order. Free shipping is Ground Select Service and NOT expedited shipping. Attention International Buyers with Economy Shipping: After a shipping label has been issued, please allow a few days for the tracking to show in the mail-stream. The courier picks up the bulk of shipments once a week at our store in Florida then transported via ground to the next dispatch center (New Jersey). During that time you will see no activity, your package is in a truck. Once received by the distribution center you'll be able to see/track your package. At arrival to your country it will be handed over to a local courier partner for delivery, who may or may not be suffering challenges of their own (ie: strikes, weather, staffing shortage, etc.)