Which of the following is NOT a factor in selecting a regulator?

When selecting a regulator for diving, several key factors come into play that significantly impact a diver's safety and experience. Reliability is crucial because a regulator must function properly under various conditions. Performance is also an essential consideration, as it determines how effectively the regulator delivers air at different depths and breathing rates. Configurability is relevant because divers often prefer regulators that can be adjusted or customized based on their specific needs, such as diving style or environment.

Weight, while it may matter for overall gear load and comfort during transport, does not significantly affect the regulator's primary function of providing a safe and dependable air supply. Therefore, while all the other factors directly influence the performance and safety of the regulator in the diving environment, weight does not play as critical a role in the operational capabilities of the regulator itself. As such, it is not a primary factor in the selection process.