Here is the first 3D slingshot presentation on youtube:
You do need some type of supported 3D glasses, including all of the cardboard types.
If you don't have 3D glasses, then you can still watch the video, just not in 3D. Simply select the right or left channel only, then you see the 2D version. It is worth it, a beautiful slingshot!
If you should be interested in the background of 3D filming and the different types of glasses, then this video could be interesting:
Enjoy! And let me know what you think.