110 Volt Fuser Kit is designed to help maintain Hewlett-Packard Color LaserJet CP4025n, CP4025dn, CP4525n, CP4525dn, CP4525xh, CM4540 MFP, CM4540f MFP and CM4540fskm MFP. The fusing assembly is the component that bonds toner to paper through a combination of heat and pressure so it needs to be maintained to maintain productivity in your HP printer.