Sky Watcher 16in. Flextube 400P SynScan GoTo Collapsible Dobsonian. The patented Flextube 400P optical system makes this telescope a clear winner delivering excellent wide-field views of deep sky objects including nebulae star clusters the globular clusters of the Hercules Globular Cluster and much more.With the Flextube 400P SynScan Sky-Watcher has improved on the basic Dobsonian design by putting the motor and electronics in the same housing as the basic model. This Dobsonian telescope includes the AZ-handle system which gives the user the convenience of a hand-held controller with a database of over 42000 objects allowing the user to experience the ultimate in accurate GoTo slewing. Lastly the redesigned AZ-handle is much more ergonomic providing a more comfortable grip and making it easier to use in the dark Specifications forSky Watcher 16in. Flextube 400P SynScan GoTo Collapsible Dobsonian: Optical Design: Newtonian Reflector Aperture (mm): 406mm Focal Length: 1800mm Focal Ratio: f/4.4 Focal Length of Eyepiece 1 (mm): 25 mm Focal Length of Eyepiece 2 (mm): 10 mm Highest Useful Magnification: 812x Limiting Stellar Magnitude: 15 Features of Sky Watcher 16in. Flextube 400P SynScan GoTo Collapsible Dobsonian: 16" (406 mm) Dobsonian-style Newtonian 1800 mm focal length (f/4.4) 2" dual-speed Crayford-style focuser with 1.25" adaptor 4-element Plossl 25mm and 10mm 1.25" eyepieces 8x50 RA erect-image finderscope SynScan hand controller with 42000 object database GoTo Dobsonian base Package Contents: Sky Watcher 16in. Flextube 400P SynScan GoTo Collapsible Dobsonian Sky Watcher 16in. Flextube 400P SynScan GoTo Collapsible Dobsonian S11840