Mirror Universe
(coexisting on another dimensional plane)
2K12 Kub

A 2K12 Kub surface-to-air missile

The 2K12 Kub (or SA-6) was a type of mobile surface-to-air missile used in the mirror universe on Earth during that planet's 20th century. (ENT: "In a Mirror, Darkly")

Although not mentioned by name, the 2K12 Kub SAM appeared in the opening credits, indicating the weapon was manufactured and used in that universe.