There is not much difference in essence. Butterfly is a relatively traditional instrument, which acts on pectoralis major. From the perspective of bodybuilding training, they are more aimed at the inner edge of pectoralis major. The so-called hand chest clamp is a later derivative device, which is comprehensive and can achieve different training purposes through the change of different arm angles. At the same time, it can be turned into an instrument for training the posterior bundle of deltoid muscle, rhomboid muscle and part of trapezius muscle.

Personally, I think the equipment for holding the chest by hand needs better control. For the trainer who can complete the standard movements, of course, the effect will be better and the contraction will be more sufficient, depending on personal preferences.

There are individual differences for reference.