This mod adds that red dot from singleplayer campaign of Call of Duty 4: Remastered.
According to IMFDB, it's a red dot sight by Tasco, so it gets the Tasco name in the files.

The mod comes with two versions of sight, one without the Riser (same as the M4A1 in COD4) and one with the riser (same as the G36C in COD4). Both version of the sight confer -1 Concealment, +4 Stability.

Known Issues:
Depending on the weapon, the Tasco scope may clip into other weapon parts, such as on my weapons which offer folded irons.

Probable Future Asked Questions:

Q: What are the weapons in the screenshots?
A:Yes.