Explore Scientific 16″ (406mm) Truss Tube Dobsonian. 1826mm Focal length f/4.5. 2″ two-speed focuser with 10:1 speeds. Deluxe Red-dot finder. Two large radial fans for fast thermal equilibrium. Lightweight and portable two-piece design allows the primary objective to store in a unique self contained aluminum housing with a lid for transport and the secondary fits inside the aluminum rocker box. Primary mirror inside mirror box weighs 52.5 lbs. Primary, secondary and truss tube assembly weighs 66.1 lbs. Rocker box weighs 22 lbs. Total weight 88.1 lbs.