The Vanguard 8x42 Spirit ED Binocular is their lightest roof prism model with ED glass lenses and full multicoating; the rubber armored housing comes in at an impressive ~1.3 lbs (600g), but doesn't skimp at all upon the optics. This is the choice for someone who values low weight and high optical quality over a more metal-based housing which weighs more but can be knocked around a bit.
Unlike a hunter's binocular, Vanguard has given the Spirit multicoatings which target the green color spectrum, for enhanced nature observation. The waterproof and fogproof Spirit has moisture-dispersing external coatings which help to shed precipitation quickly.
The 8x42 configuration is the most popular 'classic' choice for those wanting to own a single full size binocular. Most people can comfortably hold an 8x power unit for extended periods without fatigue; many cannot easily keep a 10x binocular steady. The 8x42 also provides a wider field of view than 10x42s, allowing an easier time of keeping fast-moving subjects in your vision.
Fully multicoated ED glass lenses with Emerald coatings to render full spectrum of color within green tones (essential for nature observation)
HydroGuard external hydrophobic coating upon objectives allows easier cleaning, dust/dirt resistance, and better observation in wet weather conditions
V-Max Silver coating upon P2 phase-coated BaK4 prisms for high reflectivity