What do these numbers mean?

Size:	51-16-130 mm
Total Width:	25 mm
Lens Height:	130 mm

The size numbers next to the frames are measurements in mm (millimeters).

For the listed SIZE of the frame,

• the first number is the width of the lenses;
• the second is the distance between the lenses,
• the third is the full length of the temple/arm (including the part that goes behind your ear)..
  

The LENS HEIGHT is the distance from the highest point on the top to the lowest point on the bottom of the lens.

The TOTAL WIDTH of the frame is the distance across from the far left to the far right of the frame when looking straight at it.