Low-temperature structure of indium quantum chains on silicon

A Telescopic Sight Lens Protector is provided which includes first and second lens cover assemblies for covering opposite ends of a telescopic sight and an operating assembly attached to the telescopic sight for selectively moving the lens cover assemblies axially and rotatably about the operating assembly axis. The operating assembly includes a pinion gear having an axis at right angles to the operating assembly axis and two racks resiliently biased on the operating assembly axis toward the pinion gear so as to hold the lens cover assemblies against the opposite ends of the telescopic sight. Moving one lens cover assembly axially simultaneously moves the other lens cover assembly axially in the opposite direction. Rotating either lens cover assembly about the operating assembly axis simultaneously rotates the other lens cover assembly about the operating assembly axis the same angle and direction.