Visionking Telescope 90 mm F/5.6 Refractor Astronomical Telescope with OTA DSLR Photogragh 2 Inches (Black) 90-500mm refractor has outstanding optics All optical surfaces multi-coated Refined baffle system to prevent Doublet air spaced achromatic design with 90mm aperture and 500mm focal length 2'' focuser Dovetail mounting plate for GP rail,with  tripod thread Fully Multi-Green Coated lens Compact and light weight,easy for transport