Make sure your phone OS is following: Android OS 6.0 or later, the pen can only work in the left gray area( 102*63.75mm).Go Phone "Settings" then enable "OTG" function.It will be convenient for you to take it out of the office and use it anytime, anywhere by connecting to your phone.
HUION HS64 drawing tablet comes with a battery-free pen, which make you in painting.
The working area for phone is fixed, please be informed. Its on the left of the product. HS64 only works with Android OS 6.0 or later.
You could set any function you want on the four shortcuts to increase productivity.
It can be stabilized on the table when you are drawing, and will not swing freely due to the slippery of the tablet.