What is this McCann called?

[patriotM24]

It's mounted on a Remington HS Precision stock with a serial # on the aluminum bedding of the stock, looks like they did an excellent job mounting it. I couldn't find anything about it online since I have no idea what it's called.

 

[Average guy]

Night vision bridge

 

[iceng]

Nvb, sometimes called a EFR. Embedded front rail.

https://huntsmanfirearms.com.au/catalogue/badger-ordnance-embedded-front-rail_1671/

First link I found

 

[patriotM24]

Nvb, sometimes called a EFR. Embedded front rail.

https://huntsmanfirearms.com.au/catalogue/badger-ordnance-embedded-front-rail_1671/

First link I found

Thanks, I have never seen it installed, and never seen one in the Remington Defense catalog, just wondering how common it is/was.