To activate your Glow in the Dark Shoelaces, simply wear them under or near blacklights, or charge them under a lamp or in the sun before going into a dark room, then watch them illuminate an eerie cool shade of green! Item sold per pair, meaning 1 piece = 1 package with a pair inside. Length (each lace): 40″ As with all glow products, Glow In The Dark Shoelaces do not use batteries.