I've commit a Mistake by buying vertex grip for my 5DMKIII
It doesn't have Battery Drain Problem : Contact beatween drip & Camera is not correct
It is very easy with a Magnifier to see why the Problem occur :
No Comment about Quality Control of pixel.....
I heve now to paid 30$ to resend it & wait for a long Time.......
My Recommendation : forget this Brand !!!!!
You have received Recommandations I was needed before buying.