Front element for double pushbutton Harmony ZB4. Front white/black, bezel chrome-plated metal, I/O. 2 flat pushbuttons, white I, black O. Mounting diameter 22 mm, weight 0.056 kg. Mechanical life 1,000,000 cycles. Head shape rectangular, standard. With high vibration resistance and chemical resistance, ambient temperature -40 to +70 degrees C. The modular metal program with 22 mm installation dimension combines easy installation, efficiency and modern design. Certifications listed according to UL, CSA, LROS (Lloyds register of shipping), GL, RINA, DNV, BV. Product standards according to UL 508, JIS C 4520, EN/IEC 60947-5-5, EN/IEC 60947-1, EN/IEC 60947-5-4, CSA C22.2 No 14, EN/IEC 60947-5-1.