Technical features:
* Item : 350S, 350R, 350L, 350XL
* Power: 3.5X
* Working distance: 340mm(S),420mm(R),500mm(L),550mm(XL)
* Depth of view: 50mm (S); 55mm (R); 60mm (L); 65mm(XL)
* Field of View: 55mm (S); 60mm (R); 65mm (L); 70mm(XL)
* Weight: 56.5g
* Frames: Ni-alloy or Titanium