The ABDO Rule is an extremely useful and veratile tool with the following frame measurement capabilities: Front of Rule:

• Interpupillary Distance (Lower scale for right handed person, upper scale for left handed person)
• Horizontal Lens Size
• Vertical Lens Size
• Distance Between Lenses
• Boxed Centre Distance
• Joint Size
• Crest Height
• Bridge Projection
• Distance Between Rims
• Bridge Height
• Bridge Width
• Frame Temple Width
• Frame Head Width
• Length of Drop

Reverse Side of Rule:

• Apical Radius
• Splay Angle of Pad
• Frontal Angle of Pad
• Distance Between Pad Centres
• Distance between Pad Tops
• Height of Pad Centres
• Height of Pad Tops
• Width of Pad
• Angle of Side
• Length to Bend
• Total Length
• Downward Angle of Drop
• Angle of Let-Back
• Length to Tangent.

Supplied with full instructions.