PBSVGC3EM Arca-Plate for Sony A9, A7III, A7R III with VG-C3EM Grip panning-clamp then the PMG A35 is

then the PMG A35 is not compatible

Arca-swiss compatible clamp

and you are good to go

This ProMediaGear ball head can be considered one of the best options for beginners and professionals alike

PBSVGC3EM Arca-Plate for Sony A9, A7III, A7R III with VG-C3EM Grip panning-clamp then the PMG A35 isThis ProMediaGear bracket plate is custom fitted for Sony Alpha 9 and A7 III and A7r III with VG C3EM Vertical Grip series. The bracket plate can be mounted to ProMediaGear flash brackets or L Brackets. Since it is custom designed it fits like a glove perfectly matching the camera shape, it also provides anti rotation so the plate won't slip or twist. The plate has been machined from solid Aluminum T6061 block and has hard black anodized surface