Bachmann Trains – Optical AUTO-REVERSING System – Large G Scale. 4 x 4 x 2 inches. 14 years and up. Back and forth operation at your specified speed and stopping intervals between two destinations up to 20′ apart. Includes Large Scale Auto-Reversing Speed Controller and wall power pack, power connector with track clip, two optical sensors with track clips, 3′ red power wire, 20′ green sensor wire, black double-ended sensor-to- controller wire, Trolley Car Not Included. Designed for Indoor use only. Works with Large Scale 45mm Track. Any product you return must be in the same condition you received it and in the original packaging. Please keep the receipt. We usually respond within 24 hours on weekdays. Thank you for shopping at our store.