From Filmcity…
FILMCITY Air hand held shoulder rig from TheCineCity on Vimeo.
Brings your camera even closer to action, keeps your shots stable as you move and provides absolute relaxation for extensive shooting hours.
For more details, pls visit: https://www.thecinecity.com/eshop/FILMCITY-Air-hand-held-shoulder-rig.html
Also try eBay for the Filmcity Movie Shoot Shoulder Mount Rig, (AIR) its going for around $310.