*  High quality PVC material, nose bridge design, flexible, lightweight, high transparent, easy to use. 

*  Ideal handy tool for opticians or on-line buyers of glasses.  

*  PD measuring range: 23mm~42mm each side, complete PD is between 46mm to 84mm. 

*  Three different printed scales feature, either Single PD (or binocular PD) or Dual PD (or monocular PD) can be measured in one ruler. 

*  Customizable LOGO.

*  Classic straight edge design for using with both eyes, Nose bridge design helps hold the PD ruler centered and stationary, accuracy guaranteed. 

*  Thin and flexible ruler, can be properly bent and fully fit the forehead, a single weight of 6.3 grams; 

*  PVC double-layer overlay, internal engraving process, will not wear; 

*  Special gifts for RX labs to give to opticians with good marketing effect.