I try not to publicize it.

[Because then everyone's going to want it--but if there's one person he trusts with something like this, it's Alucard. Viktor reaches for his crutch, turning it over so that he can see the underside of the handle.]

I've run an electrical current through the body of the crutch to the foot. This-- [The button, hidden where his fingers rest.] --completes the circuit. This iteration is mostly for defensive purposes, but I could make certain alterations.