ATN Doubler - DBL1 Doubler for Viper Model number ACMUDBLR01 System Description Optional focal length doubler provides selective night vision devices from ATN with an increased magnification without any additional tools. By removing the front lens and replacing it with the doubler then attaching the front lens to the doubler end user can successfully double the magnification of night vision unit. Mfg No: ACMUDBLR01 Manufacturer: ATN SKU: ATN_ACMUDBLR01