Using an extension cord with a Shark Vacuum is generally not recommended. Shark Vacuums are designed to operate optimally when plugged directly into a standard wall outlet. Using an extension cord can lead to reduced power supply, which may affect the vacuum's performance. Additionally, it may pose a safety risk if the extension cord is not rated for the vacuum's power needs. If an extension cord must be used, it is important to ensure that it is heavy-duty and rated for the wattage of the vacuum. Shark advises checking the user manual for specific guidance on power requirements and safety precautions. As always, it could be beneficial to refer to the product's official webpage for the most accurate information regarding your specific model.