Sun Products Light-Up Golf Balls: The Twilight Tracer allows you to finish a round when light is at a premium: dawn, dusk, fog and, of course, night. The white golf ball is a surlyn covered, three layer, 80 compression ball that flashes brightly seven times a second when struck. The flashing lasts for five minutes, giving you plenty of time to track and find it, and then shuts off to conserve battery power. Striking it again starts the process over, and the battery lasts an average of 450 hits (about 10 rounds of 18 hole golf) before fading.