What is the designation for nozzles that can deliver up to 350 GPM?

The correct designation for nozzles that can deliver up to 350 GPM is referred to as handline nozzles. Handlines are typically used in manual firefighting operations and allow firefighters to direct water at the fire from a safe distance. These nozzles are designed for portability and can be operated by a single firefighter or a small crew. Their flow rate is efficient for attacking structural fires and is manageable enough for firefighters to control while still delivering a significant volume of water.

In the context of the other options, master nozzles usually flow higher than 350 GPM, making them less suited for the specified flow rate. Deck guns, which are mounted on apparatus and can deliver large volumes of water, typically exceed the 350 GPM flow rate as well. Fog nozzles can vary in flow rates and are designed to provide a wide spray or mist, but they are more specialized and may not be explicitly designed for a standard delivery of up to 350 GPM like handline nozzles. Thus, the designation of handline is most appropriate for nozzles that operate within the specified flow range.