Adjustable DPI: 800 / 1200 / 1600 dpi
DPI values are changed from 4 steps to 3 steps from Mar. 2019

101K Silent Mouse Click 33.7dB (Wheel is not silent)
Second hand sound 20dB
Leaf bump sound 20dB
Whispering sound 30dB
library 40dB

JSCO noiseless mouse 101K is the steady seller among the noiseless mouse.
It is very useful at library and school and university. The mouse click sound is quieter than the keyboard click sound that you are using.

The mouse driver is auto-detected by windows, but if you use windows 2003, it may require installing the universal mouse driver (HID standard mouse)

The scroll wheel is not noiseless, if you use the scroll wheel frequently, you can set the wheel frequently, you can change the mouse setting in control panel.

The default value of the number of lines to scroll is 3 lines. If you change the value over 3, you can easily scroll the screen with little movement silently.