This is a Leupold Sun Shade known as the Scopesmith, model 52350.
Protect your Leupold riflescope's objective lens from rain and glare. The 2.5 and 4 inch 50mm Lens Shades can be threaded together to create custom lengths. Fits all Leupold 50mm objective riflescopes manufactured after 2004.
Features:
Matte black finish