One pair (2) HO scale grade crossing gate signals by NJ International, Inc. Brass construction with red LEDs and the necessary dropping resistors installed. Red & white gates with 'A' type arm that swing freely and can be animated. Nice detail.

Detect trains and animate these signals with the GCP Grade Crossing Pro controller by Logic Rail Technologies (sold separately).

Animate the crossing gates with Tortoise #800-6000 slow motion switch machines from Circuitron (sold separately).

Add realistic sound to your crossing signal with a Grade Crossing Bell sound module from ITT (sold separately).