This Harmony ZB, consists in a clear silicone boot. It is compatible with Harmony XB4 and XB5 projecting and push-push circular heads. This silicone boot is ideal to complement a control unit and adapt it to stright hygiene and cleaning requirement of stringent industries. It is transparent, allowing users to see colors and marking of the underlying button and is perfectly formed-fit with Harmony push-buttons. It is chemical resistant, making it ideal for operation in harsh environments requiring frequent chemical cleaning. The silicon boot prevents growth of bacteria in joints and gaps: ideal for high hygiene environments like food and beverage industry.