Feature: The pd ruler can help you when you want to buy glasses online Put the notch over your nose, as close to your eyes as you can, then find the middle if your pupils in a mirror, read the line closest to the middle of the pupils. Come With 4 different types rulers which suits different need, and 3 types are soft rulers , and 1 type are hard rulers. Note that this does not come with any instructions, so if you don"t know how to take a PD measurement, you will need to look that up on the internet. Material: Plastic, Length (mm):180/7" Width(mm):25/1", Quantity: 4PCS. Note: Size for manual measurement, there may be a 0 to 2 cm error, belongs to the normal phenomenon. And due to the difference between different monitors, the picture may not reflect the actual color of the item. Thank you Package includes: 4PCS X PD Rulers . Our products are made with the highest quality materials and are designed to provide you with the best possible user experience. We strive to ship out all orders within three days of purchase, and the estimated delivery time is 8-15 days. When shopping, please pay attention to the size and dimensions of the product to ensure that it meets your needs. In the title and , we have provided detailed information about the product, including its features and specifications We want you to be completely satisfied with your purchase, so if you have any questions or concerns, please don''''''''t hesitate to contact us. We are here to help and will do our best to assist you. Thank you for choosing our product. We hope you enjoy it