Cheap And Discounts DIY Astronomical Refracting Telescope Dia.73mm Optical Glass Focal Length 280mm/316mm Doublet Optics Objective Glass Lens Wholesale. Buy Directly From Merchant Ruite Professional Optical Trading Co., Ltd. Enjoy ✓Free Shipping Worldwide! ✓90 Days Buyer Protection. ✓Easy Return. ✓Money Back Guarantee.