HD4 circuit-breakers are available in fixed or withdrawable versions. The withdrawable version is available for CBF fixed parts and CBE and PowerCube enclosures, UniSafe and UniGear type ZS1 switchgear. HD4 circuit-breakers are used in power distribution to control and protect lines, transformer and distribution substations, motors, transformers, capacitor banks, etc. They are also highly suitable for retrofitting, where the insulating materials of circuits may be sensitive to dielectric stresses.