The new Barr & Stroud Sierra range of binoculars are a blend of superb optical quality and rugged refinement. The Barr & Stroud Sierra 10×42 binocular has an additional 2x magnification over the other 42mm objective lens model in the Sierra range. This extra magnification can be useful to get you closer to the action but there are trade offs. It also needs more care to hold steady as any movement will be amplified a further 2x making it more likely that additional support such as a tripod, monopod or hide clamp will be needed. That said if you can hold them steady and they will provide stunning close ups that the 8x can only provide by getting closer to the subject, and if that happens to be a pride of lions in the Masai Mara I’d go for the extra magnification every time!The Sierra range from Barr & Stroud feature rugged construction combined with brilliant optics. They are waterproof to a depth 1.5m of water for three minutes, plenty of time to retrieve them if you have dropped them in a stream or puddle. This ability is further enhanced by the binoculars’ rubber armoured body which protects it from shocks and knocks. this binocular is truly weatherproofy Multi Coated optics are standard features of the Barr & Stroud ‘Sierra’ range as are BaK-4 phase coated prisms. This degree of sophistication ensures that as much light as possible is transmitted through the optics which results in a super bright contrast rich images of high colour fidelity for the user even in low light conditions where less expensive optics and coatings result in a dramatic loss of performance. The rapid focus mechanism takes the user from close focus to infinity in less than one turn of the focus control knob, which ensures that you can follow the action however fast it is happening Sierra 10×42 are supplied with carrying case, rain guards, tethered lens caps, straps and lens cleaning cloth.