Pick your LensMaster Gimbal Head
You have a choice here of the Single Side Mount or the Full Twin armed Gimbals.
Images above show what you get with each gimbal.
RH1 and RH2 Gimbals are fitted with an Arca Swiss type clamp and come with two plates, a 50mm and 140mm lens plates so are ready to use.
Other size lens plates are readily available from most good photographic stores, there isn't a one plate fits all owing to the large combinations of lens, camera, converter, and battery grips available.
In general a larger lens plate allows more front/back movement aiding the balance setting and also allowing the safety pins to fully engage.