1.Replace regularly:nose pad might get dirty after long-term wear, it is recommended to replace every 3 to 5 months for hygiene and better wearing experience, the sufficient quantity also makes replacement much easier2.Hole's size: rectangular hole for installing onto glasses nose pad is 7 mm (0.28 inch) long and 4 mm (4/25 inch) wide, please measure before buying3.Main function: the silicone are easy to install without extra tool's help, saving you from slipping glasses caused by small nose or weighty glass frame4.Anti-slip and height-increasing: these pad covers can not only increase the height, making the eyeglasses fit you more, but also prevent slip, giving you more comfortable eyeglasses wearing experience5.Package includes: you will receive 10 pairs silicone , enough quantity for meeting your daily wear and change needs