The Ostara S-HR range of Plössl eyepiece comes with high optical and performance. With 4 Lens Elements in 2 Groups, the lens glass is fully multi-coated to enhance light transmission while reducing the reflections. The body is made from an aluminium alloy which makes it hard and lightweight. This Plossl eyepiece offers a wide field of view, and therefore it's ideal for a wide range of observational applications such as planetary and deep-sky viewing.