dsa bulb tube focus is generally greater than or equal to three, right?

Yes. DSA ball tube focus is greater than or equal to three, with focus automatic switching function: large focus ≥; in the focus ≥; small focus ≤; large focus power ≥ 110kW; in the focus power ≥ 54kW; small focus power ≥ 20kW; ball tube cooling using circulating water cooling and oil cooling double cooling. The ball tube is the core component of DSA, it is not the equipment that can be used alone, DSA has strict precision and matching requirements for the ball tube, it is necessary to purchase the original Siemens ball tube in order to ensure the matching of the whole machine with the DSA, to achieve safety, high efficiency and the best image quality.