The external service Id which permits registration of an alternate implementation for duct fitting and accessory pressure drop calculation. To use this service, programmers implement a server class that derives from IDuctFittingAndAccessoryPressureDropServer.

public static ExternalServiceId DuctFittingAndAccessoryPressureDropService { get; }

Public Shared ReadOnly Property DuctFittingAndAccessoryPressureDropService As ExternalServiceId
	Get

public:
static property ExternalServiceId^ DuctFittingAndAccessoryPressureDropService {
	ExternalServiceId^ get ();
}