Diagonals provide a user-friendly observing position for refractors and Cassegrain telescopes. The Explore Scientific 2" Diagonal Mirror here is precision machined from aluminium and contains carbon fibre parts. The large eyepiece port diameter of 2"(50.8mm) is ideal for modern wide angle eyepieces and a non-marring brass compression ring holds the eyepiece in place securely. The dielectric coating of the mirror delivers 99% reflectivity and is very durable against environmental influences. A step-down reducer to 1.25"(31.8mm) is included, so all of your 1.25" eyepieces and accessories can also be used.