1. Portability: Evaluate the weight and portability of the blower, especially if you need to transport it frequently or store it when not in use. Lightweight and compact designs are convenient for handling and storage.

2. Safety: Ensure that the blower meets safety standards and regulations for inflatable structures. This includes features such as grounded plugs, safety guards on the intake, and compliance with electrical safety standards.

3. Availability: You can find 350-watt blowers for bouncy castles and other inflatables from various suppliers, including online retailers specializing in inflatable equipment, rental businesses, and stores that cater to outdoor and recreational equipment.

When choosing a 350-watt air blower for a bouncy castle or similar inflatable, consider the specific needs and size of your inflatable structure to ensure the blower provides sufficient airflow for inflation and meets safety requirements for use with the inflatable.