Best 35 mm made in my humble opinion and I tried them all. better see my other things .....want pne way nicer looking than the Sawyer same great build JUst look for Pana-vue viewer . I lave some of these Leitz Bi-Lens and they have fallen to pieces..... Makes your regular slides look like 3D and less eyestrain also...you will never hear surf music , I mean go back to regular viewers, again. A complicated set or mirrors shifts the images and overlaps them a little giving 3D like images but not true 3D that takes a left eye and a right eye picture. NOw want it electeric look up sayers or pana-vue transformer I have last one of each....you can save a little by comining must put in carts and wait for invoice...