DIN EN ISO 1366 defines VD as follows: absolute value of the distance between the rear surface of the spectacle lens and the corneal apex measured along the line of sight, i.e. orthogonally to the plane of the rim. The ...

The transparent sighting bar has one scale on its surface and one inside. Take your VD reading when you see the two scales in alignment. The millimetre values on the scale refer to the eye-side vertex of a trial lens ...

UB 6: approx. 61 g UB 5: approx. 48 g UB 4: approx. 64 g UB 3: approx. 58 g UB 3+: approx. 52 g (10 % lighter than the UB 3) note: specifications are subject to change!

Yes, with the exception of the UB 3.

UB 6: four nose pads in total UB 5: three nose pads in total UB 4: three nose pads in total UB 3+: two nose pads in total

Yes, provided that the UB 4 has round operating elements only. They do not fit on older UB 4 models that have conical operating elements for adjusting pupillary distance.

No, each lens holder is designed to precisely match the trial frame it is intended for, so the lens holders cannot be switched between the UB 4 and UB 6.

Yes, the nose pads of these two models are interchangeable.

No, each polarizing filter is fine-tuned to the design of the trial frame it is intended for, so it cannot be switched between the UB 4 and UB 6.

No, each polarizing filter is fine-tuned to the design of the trial frame it is intended for, so it cannot be switched between the UB 6 and UB 4.

No, the nose racks differ in design, so they cannot be switched between the UB 4 and UB 6.

No, the nose racks differ in design, so they cannot be switched between the UB 6 and UB 4.