Leupold put out a warning detailing a recent surge of counterfeit Mark 4 and Prismatic riflescopes. The scopes’ apparent origin is the People’s Republic of China, and bear many of the marks and trade dress of current Leupold & Stevens riflescopes. If a scope seems suspect, the serial number can be called in to 1-800-LEUPOLD to confirm its authenticity. The counterfeit scopes can also be identified by several characteristics not found on authentic Leupold scopes, as seen in the images below.
Counterfeit Mark 4
Counterfeit Prismatic
leupold.com/resources/counterfeit-warning/