What kinds of products are manufactured to be parabolic?
Name some things that can be elliptical.
Parabola:
satellite dish, headlights
ellipse:
The “whisper chamber” in the United States Capitol is an ellipse, stand at one focus and whisper, and anyone at the other focus can hear you with perfect clarity, even though they are much too far away from you to hear a whisper normally. The Mormon Tabernacle in Salt Lake City was also designed as an ellipse, to provide a perfect acoustical environment for choral and organ music.