Square D (Schneider Electric) ZB5AVG5 Harmony Light Block Assembly. Schneider Electric Harmony™ Light Block Assembly, Series: ZB5, 22 mm Dia Size, LED Lamp, 120 VAC, Screw Clamp Terminal, Yellow, 1.18 in W x 1.26 in D x 1.65 in H Dimensions. Additional Description: SQD -ZB5AVG5 MOUNTING BASE W 120V YEL PROTECTED LED PROTECTED LED. Catalog Description: Harmony XB5, Light block with body/fixing collar, plastic, orange, integral LED, 110 120 V AC.