Swing out and back with your hands close together in a Close Grip. At the platform, lift your legs up around the bar hold them straight with the backs of the knees against the bar. As you approach the front end, hook your legs onto the bar and unfold your body (letting go of the bar) so your chest rises towards the sky. Finally let go of the bar to make the catch.
This trick can also be performed with the legs hooked on immediately at the back end.
You can find out more about this trick in my books:
Thanks to Diana for providing a video for this page.