The pupillary distance ruler for eyeglasses is designed to offer precise measurements for both single and dual PD. This optical instrument is ideal for opticians, optometrists, and eyewear . To use, align the ruler with the center of each pupil and read the measurement directly from the scale. This ensures that the eyeglasses will fit comfortably and provide correction. Features -Color:White -Material:Aluminum -Size:17.50X2.30X0.03cm/6.88X0.90X0.01in -Optometry : this pd ruler is a crucial tool for optometrists, aiding in the accurate measurement of pupillary distance for proper lens alignment -Aluminum: made from aluminum, this ruler is and resistant to bending, ensuring precise and reliable measurements -Dual measurement scales: features dualsided scales with millimeters on one side and inches on the other, meeting diverse measurement needs -Convenient and portable: the compact, rigid design allows for easy portability and use, making it ideal for both professionals and home users -Wide range of applications: suitable for optometrists, optical shops, ophthalmologists, and home use, providing a versatile solution for eye measurements Package list: 1 x Pupillary Distance Ruler