From the project page:

The aerial cinema experts at Teton Gravity Research release the first ultra HD footage of the Himalayas shot from above 20,000 ft. with the GSS C520 system, the most advanced gyro-stabilized camera system in the world. Filmed from a helicopter with a crew flying from Kathmandu at 4,600 ft. up to 24,000 ft. on supplemental oxygen, these are some of the most stable, crisp, clear aerial shots of these mountains ever released, which include Mt. Everest, Ama Dablam, and Lhotse.