YKK Slider #10 Vislon White Metal Single Locking Pull is specifically designed for use with YKK #10 Vislon Continuous Zipper Chain. This zipper slider features a low profile and a locking mechanism designed to grip the zipper chain to keep the slider from moving until the pull tab is tugged. These zipper sliders are specially designed to resist corrosion and UV rays. Single pull sliders can only be opened from one side.