NEW DESIGN TCS Keep-Alive® (KA) devices are used to supply power to decoders during times of power interruption due to dirty track or problematic track work. Newly-redesigned and coming in at half the size of a KA3, the KA1 will power HO or N scale locomotives with approximately one-third of the capacitance of KA3/KA4 devices (depending on the locomotive and motor). This Keep-Alive® includes a Blue and a Black w/ White Stripe wire to attach it to a decoder. Dimensions:1.063" x 0.35" x 0.244" or 27mm x 8.9mm x 6.2mm Scale: HO Scale N Scale Input Rating: 12 to 16V SKU: 1454