YOU ARE LOOKING AT A TRAIN CONTOL SYSTEMS (TCS) KA4 DECODER. The KA4 is a Keep-Alive™ (KA).The Keep-Alive™ (KA) devices are used to supply power to decoders during times of power interruption due to dirty track or problematic track work.
KA4 will power an HO-Scale locomotive with headlights on for approximately 6 to 20 seconds (depending on the locomotive and the efficiency of the motor).
This Keep-Alive™ includes a blue and a black w/ white stripe wire with which to attach it to a decoder.
Dimensions: .52" x .52" x .45" or 13.22mm x 13.22mm x 11.55mm
Model: 1668 Shipping Weight: 0.01875lbs
IT IS NEW IN BOX AND RETAILS FOR $26.95. THANKS FOR LOOKING AND GOOD LUCK.