Flat braided copper strands that are attached to the bottom of the guide flag and transfer electrical current to the motor.

Perhaps it would be more correct to say they transfer electrical current to the motor lead wires? (That last line was my Edit)

Also one type of electrical conductor which can be laid on routed wood tracks to distribute the power to the track - usually 1/4" (6.35mm), but sometimes 3/16th; or for HO scale tracks, 1/8th can be used.