A desktop machine with two probes to massage the back is usually called a "two-headed massager". This is because this massager has two massage heads that can massage the back at the same time. Each massage head is usually equipped with rotation or vibration function, which can provide different massage methods and strengths, thus helping to relieve muscle tension and fatigue.

Double-head massager has the following advantages in back massage:

1. Double-head design: The design of the double-head massager enables it to cover a larger back area at the same time and provide a more comprehensive massage effect. In this way, users can enjoy a more effective massage experience in a shorter time.

2. Multifunctional selection: Double-headed massagers usually have multiple massage modes and speed adjustment functions, which can be adjusted according to individual needs. Users can choose the appropriate massage method and intensity according to their own preferences and comfort.

3. Convenient and easy to use: Double-head massager usually adopts desktop design, which can be stably placed on a chair or bed, and users can control the position and strength of the massager by themselves. This design is very convenient to use, and users can massage independently without the assistance of others.

In addition, modern double-headed massagers may also have other functions, such as heating function and remote control, to improve massage effect and comfort. Double-headed massagers are widely used in families and workplaces to help people relieve back discomfort and relax stress.