Check the listing for details. Atlas HO Scale Bumper code 100 N/S #843 modified with 2 way LED light added. Color: Black, Condition: Used. Listed at 7.50 USD. Atlas HO Scale Modified LED lighted Bumper - Nickel Silver track This is a New Atlas(TM) (part #843) HO Code 100 Nickel Silver Bumper has been adapted to accommodate an LED The unit supplied comes fully assembled with the Red/Yellow bidirectional LED already installed. The LED has been permanently installed in the rear socket and Lights with current in both directions. RED as the train approaches the bumper and Yellow when the train leaves in DC mode when using NMRA recommended current control. (see photos on this listing or modeltrainsounds.com) Package comes fully assembled 1 new HO Scale modified Atlas Bumper with Nickel silver Code 100 Track. Note: If using with our Auto-reversing system please send a note as special wiring is required. There is no additional charge when a minimum of 2 units are ordered. No soldering is required. LEDs light when track current exceeds 3.5 Volts in DC mode BUY IT NOW $7.50 + Shipping and Handling $4.50 for one or more.