Smooth Speed Adjust
The ability to smoothly change the feed rate of the material. The speed adjust allows you to set the mode of operation of the pen to the circumstances: for example, a low speed will be convenient for fine work, and a high speed is so for large elements. Specifically, the smooth speed adjust is convenient because it allows you to select almost any speed in the range from minimum to maximum.
In addition to this type, there is also a step adjustment, for more details, see “Number of Speeds”.
Number of Speeds
The number of fixed speed settings provided in the pen. This spec is specified only if there is more than one such setting.
The speed control allows you to adjust the mode of operation to the circumstances: for example, a low speed will be convenient for fine work, and a high speed is so for large elements. And the more speed settings there are in the pen, the wider the choice for the user to configure the device more accurately. In the most advanced models, the number of speeds can reach eight.
Note that the speed adjust can be not only stepwise, but also smooth (see above).
Auto Power Off
Automatic power off of the pen for being idle for a while. Usually, auto-off triggers after a few minutes.
This feature is found mainly in models with a "hot" type of operation (see "Product Type"). It saves energy and reduces the risk of getting burned by accidentally touching the pen that is left on. However, there are also "cold" models with auto-off.