The 546B Legs are a two-stage, extremely rigid, stable set of tripod legs. Able to carry loads up to 44 pounds (20 kg), it has an aluminium top casting with a built-in 75mm half ball, allowing it to be used with Manfrotto’s professional half-ball video heads with 75mm fittings. Its aluminium twin-strut legs feature adjustable locking levers that can be tension-set to guarantee complete locking power even after years of use and wear; the spiked feet with removable rubber shoes are suitable for any surface from smooth, delicate floors to uneven ground.
The 504HD head has a Payload limit of 12Kg so its best not to exceed this on the head. However the legs being able to take more means that you could attach more weight to the legs such as adding a Jib arm and they would remain secure.