Is it possible that scrotum/testicular electro stimulation cause any harm to the testicles?

I am thinking about buying the Oxballs Daddy Electro which has electrodes that contact the bottom of the scrotum but also as it's a cock & ball sheath the scrotal skin is in close proximity with the testicles, so wondering if there's any chance of damaging my balls, specifically if I want to be a daddy in the future!?