1. Turnable acoustic gradient index of refraction lens and system

2. The turnable Loudspeaker tubes ensures the optimum radiation angle as well as individual design solutions.

3. An adjustable vent nozzle comprises first and second nozzle members (1, 2) turnable relative to one another.

4. Angulating borescope, bending borescope, steerable borescope, pivoting camera) is an inspection optical device or video camera equipped with a turnable probe tip