Square D (Schneider Electric) ZBVG5 Harmony Light Module. Schneider Electric Harmony™ Light Module, Series: ZBV, 22 mm Dia Size, LED Lamp, 110 to 120 VAC, Screw Clamp Terminal, Front Mounting, Orange. Additional Description: SQD -ZBVG5 PUSH BTN LIGHT MOD 22MM 110-120VAC XB4. Catalog Description: Harmony XB4, Light block for head Ø22, orange, integral LED, 110...120 V AC.