Red Dot Sight

Not to be confused with the specialization in Battlefield: Bad Company 2 of the same name. The Red Dot Sight is an attachment that has been featured on a few weapons in Battlefield 2

Battlefield 2
A red dot sight appears on some weapons as a default attachment. It comes on the AKS-74u, M4A1, and P90. Although the frame of the sight is different for each weapon (a Kobra sight for the AKS-74u, an Aimpoint M68 sight for the M4A1, and an FN micro red dot for the P90), the actual dot is the same amongst all of the different sights.

Battlefield 3
The red dot sight is a confirmed weapon attachment and was on the Gamescom Multiplayer Fact Sheet released by EA.

Trivia

 * In Battlefield 2, the PLA QBZ-97 does not come with a red dot sight, making it the only Special Forces default weapon to not have a red dot.