That's a 360 video rig for GoPro, the system it's compatible with GoPro Hero 3, Hero 3+ and Hero 4.
I have designed the whole rig by my self using Google Sketchup (SKP files availables upon request). The system shape permits the using of USB external power supply in order to solve the limited Gopro battery duration when wifi network it's turned on (necessary for remote triggering the cameras)
Each individual camera holder uses a M3 nut and bolt (hand operated in my implementation). The nut for the stick it's a regular 1/4" for tripod.
All nuts can be fixed into the hole using an soldering iron.
Once the six Gopro cameras are mounted you can trigger it at once using wifi remote control. It's highly recommended connect all of them to an external power supply bank (see pictures in gallery) due to the heavy battery drain when wifi it's turned on