Reusable hand pieces which contain piezoelectric transducers that convert electronic energy into ultrasonic vibration to power Harmonic Devices. The Harmonic Blue Hand Piece is used with Harmonic Focus and Harmonic Synergy Blade product lines. The Harmonic Hand Piece is used with Harmonic ACE+7 Shears and Harmonic ACE+ Shears product line as well as laparoscopic blades. Harmonic HD 1000i Shears do not require a hand piece.