SGOEDY-109 2.5X420mm Binocular Clip Loupes Lab Head Magnifier w/Clip-on

When clipped to glasses, do these easily flip up out of the way?

Does it come with a case to store them in?

Is the working distance actually 420mm, I have previously ordered a pair of these from another seller and those were only a 200mm working distance

Can I clip these onto my prescription glasses?