Technical features:
* Item : 350KS, 350KR, 350KL, 350KXL
* Power: 3.5X
* Working distance: 340mm(S),420mm(R),500mm(L),550mm(XL)
* Depth of view: 45mm (S); 45mm (R); 45mm (L); 45mm(XL)
* Field of View: 55mm (S); 60mm (R); 65mm (L); 70mm(XL)
* Weight: 78g
* Frames: Ni-alloy or Titanium
