These are paracord lanyard / key fobs / Zipper Pulls with multiple possible purposes. Each lanyard is made from 550lb parachute cord - gutted - inner strands removed so it can be fd through tighter holes. The skulls are made of an acrylic plastic material. Each lanyard measures approximately 5" overall length. Just feed the loop through a hole or around an object and feed the skull end through the loop, tighten and voila, you have attached a handy lanyard to better improve your grip and grasp of objects like Knives, zippers, rings, sheaths, weapons, guns, and any object with a hole of at least 4mm in diameter. If you are not satisfied with your purchase for any reason we will provide you with a 100% money back return policy. Feel free to inquire with us about custom lengths and colors.