With Choice Specs, this set fulfills the role of a powerful early- and mid-game wallbreaker. If the opponent has a Pokemon that is immune to Electric, be sure to take it out early on in the match so that Jolteon can freely spam Volt Switch.
Thunderbolt is always a reliable 100% accuracy Electric STAB move, paired with Jolteon's 110 Special Attack, it will deal a fair chunk of damage.
Volt Switch allows the user to pivot Pokemon in the case of a bad matchup, etc.
Hidden Power Ice gives Jolteon the ability to deal 4x damage towards popular threats such as: Salamance, Gliscor, Dragonite, etc.
Shadow Ball gives the Jolteon a reliable coverage move to attack Ghost and Psychic Pokemon.
Hyper Voice functions as additional neutral coverage, not as spammable as Shadow Ball but doing a little more to neutral Pokemon like opposing Jolteon.
Signal Beam allows Jolteon to take on the Grass-types that resist Thunderbolt, such as Rotom-C; it also sees use against Malamar.