One product repair kit comes in the box with each new heater purchased. They include two filters, two o-rings, two fuses, one nozzle, and one nozzle wrench. A basic kit to cover your bases.
Note: The 0.75 kit is to be used only for KBE5L models with a high/low switch. If you own a KBE5S, or a KBE5L without a high/low switch, you should purchase the 0.85 kit.