16" Jacket Zipper, YKK #5 Aluminum Metal ~ Medium Weight ~ Separating ~ 519 Red (1 Zipper/pack) 16" Jacket Zipper, YKK #5 Aluminum Metal ~ Medium Weight ~ Separating YKK Color 519 Red (1 Zipper/pack) YKK aluminum zippers are made from the highest quality metal. Thoroughly tested to ensure strength & reliability. Aluminum Teeth.