Zapper is a cute nickname for an electro-wand that is used as part of electrostimulation. These typically look like a magic wand a wizard would use, except they're used to send shocks to the body. Zappers are often used as part of DS play in which the dominant shocks the submissive. Though it sounds scary, zappers feel like a little sting. Still it is 100% okay if they're on your hard-no limit list. You can still be kinky and cool without zappers—I'd be shocked (shocked!) if they didn't scare you a teeny bit.
