Beautronix toning device (St Just TR19)

Old but hopeful of new home. In briefcase , clasps do not bind, but all else in good condition, pads can be placed in various ways, to tone muscles by gentle electrical pulses. Elastic straps to hold pads in place. Batteries are needed inside and then it plugs into socket, I think I remember. Possibly works not plugged in. Working order when last used….