Is often used as a type inside a USB_NODE_CONNECTION_INFORMATION_EX structure, hence the need for the "Pack=1"

struct USB_NODE_CONNECTION_INFORMATION_EX

Structure USB_NODE_CONNECTION_INFORMATION_EX

typedef struct _USB_NODE_CONNECTION_INFORMATION_EX {

} USB_NODE_CONNECTION_INFORMATION_EX, *PUSB_NODE_CONNECTION_INFORMATION_EX;

   int nBytes = Marshal.SizeOf(typeof(USB_NODE_CONNECTION_INFORMATION_EX));

     USB_NODE_CONNECTION_INFORMATION_EX NodeConnection = new USB_NODE_CONNECTION_INFORMATION_EX();

       NodeConnection = (USB_NODE_CONNECTION_INFORMATION_EX)Marshal.PtrToStructure(ptrNodeConnection, typeof(USB_NODE_CONNECTION_INFORMATION_EX));

   USB_NODE_CONNECTION_INFORMATION_EX connection = new USB_NODE_CONNECTION_INFORMATION_EX();

   size = Marshal.SizeOf(typeof(USB_NODE_CONNECTION_INFORMATION_EX)) + 32 * Marshal.SizeOf(typeof(USB_PIPE_INFO)); // Assuming 32 should be enough, you can make this larger

     connection = (USB_NODE_CONNECTION_INFORMATION_EX)Marshal.PtrToStructure(ptr_connection, typeof(USB_NODE_CONNECTION_INFORMATION_EX));

     if (bytes_returned != Marshal.SizeOf(typeof(USB_NODE_CONNECTION_INFORMATION_EX)))

       int num = (bytes_returned - Marshal.SizeOf(typeof(USB_NODE_CONNECTION_INFORMATION_EX))) / Marshal.SizeOf(typeof(USB_PIPE_INFO));

                       + Marshal.SizeOf(typeof(USB_NODE_CONNECTION_INFORMATION_EX))