This durable adjustable non-slip mask strap hook is made of high quality silicone. Easy to adjust the length of the earloop with the 3-level adjustment hook based on your needs, so it will not cause any discomforts to your face skin and leave skin indentations. It is a wonderful giveaway for the people who need to wear masks for a long time such as medical staff, dust-workers, food-workers, and so on.