Prisma di Amici ClickLock BBHS® 90° 2"

This is is the only erect-image prism in the world which is suited for astronomical observation at high magnification. This prism is hard-silver-coated and protected against aging (as proven already...). Dirt is no problem because the silver-coating is applied onto the reflective surfaces. Other roof-prisms without this silver-coating will collect dust at the roof faces. As a result the image is getting dimm and hazy over time. This 2"/90° Amici roof-prism is largely superior to other erect-image prisms in brilliance and maximum magnification. Unfortunately, it is a luxury product for experienced observers, manufactured in very small numbers.