| Description | It is a BIO (Amber) with headband mounted control. | It has a tilt-up feature, fully adjustable optics and a bright halogen bulb. | It has a tilt-up feature, fully adjustable optics and a bright halogen bulb. | It is a BIO (Cobalt blue) with headband mounted control. | It offers an interpupillary distance of 49-74 mm. The extra filters, small pupil accessory and power source can be bought separately. |
| Features | Classic BIO (Amber) includes an AC adapter. | It features true stereopsis through dilated and small pupils, built-in small, intermediate, and large apertures, light and durable adjustable headband, synchronized convergence and parallax adjustment, sealed dust-free optics and anti-reflection coating. | It features true stereopsis through dilated and small pupils, built-in small, intermediate, and large apertures, light and durable adjustable headband, synchronized convergence and parallax adjustment, sealed dust-free optics and anti-reflection coating. | Classic BIO (Cobalt blue) includes an AC adapter. | It features true stereopsis in pupils, is maintenance free and fully convertible to a headband mounted system. It has dust sealed optics. |