Designed for generators manufactured prior to 2013. (Use a round filter). Scheduled maintenance is a necessity for all standby generators. This Liquid-Cooled Scheduled Maintenance Kit offers all the components necessary to perform a complete maintenance on Honeywell liquid-cooled generators. Oil and coolant will need to be purchased separately based upon manufacturer recommendations listed in your owners manual. Maintenance is recommended at every 200 hours or 2 years. If running in a dusty environment, more frequent maintenance may be required. Further maintenance details can be found in your generator owner's manual.