The Lite 3D Viewer is a Parallel Format (side-by-side) Viewer made of card stock for stereo prints. It also works well as a Computer Monitor Viewer for medium sized images. Squeeze viewer to focus. Inexpensive, lightweight, foldable and mailable, it folds flat to the thickness of its lenses (7 mm) and fits into a 4 x 6 photo album sleeve. The lenses produce very clear and sharp images. Comes with handy carrying case. Viewing Print Size: Standard 3R (3.5 x 5 inches) prints or 4R (4 x 6 inches) prints Screen Image Size: Optimized for 5 - 7 inch wide screen images Viewing Format: Side-by-side (Parallel) format 3D Viewing Distance: 2 - 20 cm from 3D photograph to front panel of viewer Eyeglasses: Can be worn or taken off while using the viewer. Lens: Clear plastic lenses with prisms Viewer Size: 138 x 76 x 7 mm folded (L x W x D) - 7mm is the thickness of the lenses Viewer Case Size: 142 x 81 mm (L x W) Material: Plastic coated white card paper with the inside surface printed black to create the dark viewing chamber