Toggle visibility on parts of a model

First off, total newbie here. Second, I have a character model that I exported in from Max as a .obj, and it’s made up of separate pieces (a pelvis, abdomen, torso, combined shoulder/upper arm piece, lower arm, hand, etc etc). Her arms/hands have a few different states of animation: one is an open palm with fingers pointing straight out, another is a relaxed open palm with fingers bent inward a bit, another is a fist, and the fourth and final one is a large gauntlet on her hand, but her wrist is non-articulated. I’d imagine that I would have to properly align all of these separate pieces in the exported model in the first place (which I’ve done already - the hand variations all become one blob attached to her upper arm/shoulder piece). My question, thusly, is this: how can I make it so that visibility on each hand variation (show straight open palm in one part of an animation, fist in another, gauntlet in another, etc) can be “toggled” on/off in different phases of an animation?

You could use Animation Notifies to toggle on/off the pieces at different parts of the animation. More info on those here: