Schneider Electric ZB4BZ2105 Round guard for 40mm Emergency stop, Harmony XB4, plastic, yellow, 76.2mm. Official Schneider characteristics include Range of product: Harmony XB5 Harmony XB4; Product or component type: Guard; Accessory / separate part category: Protection accessory; Accessory / separate part destination: Ø 40 mm emergency stop push-button; Colour: Yellow; Quantity per set: Set of 1; Material: Plastic; Net weight: 0.058 kg. 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.