Schneider Electric ZB4BZ009 Body/fixing collar for electrical block, metal. This Harmony XB4, body/fixing collar allows to connect together XB4 heads with contact or light blocks. It is made of metal. The base unit to start assembling your Harmony XB4 heads and bodies. Official Schneider characteristics include Range of product: Harmony XB4; Product or component type: Body fixing collar; Accessory / separate part designation: Fixing collar; Accessory / separate part type: Body fixing collar; Accessory / separate part category: Mounting and fixing accessories; Material: Metal; Head type: Standard; Accessory / separate part destination: Electrical block. Harmony XB4 devices use a chromium-plated metal bezel and are designed for robust panel operation where clear manual control, indication or machine safety interfaces are required.