BE CAREFUL>>>
My Gitzo Leveling base unbeknownst to me developed a crack in the casting just above the slot for the tensioning device. When I placed the rig on my shoulder the leveling base completely seperated, the cup remained affixed to the tripod, while the upper part of the base came crashing down along with my Wimberley head and camera gear.
Luckily only the rear flange of my 500mm suffered damage.
I have since ordered a RRS replacement.
Best,
Chas

