The general lithium drill is a three-stage reduction gear that changes the high-speed low-torque of the motor into a low-speed, high-torque working state of the electric drill. If there is no extra function, the drill is fixed speed, which is "single speed".
The "two-speed" is a slightly extra design, you can choose to let the second-stage reduction gear not participate in the work, in this way, the final electric drill will get higher speed, this is the so-called second speed mode, "high speed". Thus, the electric drill has two speed modes, the so-called "two-speed". Of course, in the high speed mode, the corresponding torque is also lower because the total output power of the motor is constant.
The two-speed ratio of the single speed can make the use of the electric drill more detailed and enlarged (screw and drill, and the material of the drilled object is different, the required speed and torque are different), very practical