# When import volumetric data (spin density of CHGCAR) to VESTA which option should we pick here?

I am trying to plot SPIN DENSITY isosurfaces using VESTA. I have used vaspkit option 312 to create SPIN.vasp file which contains spin density from the CHGCAR. Now, when I import data to VESTA it shows the window below to convert or not convert data.

My question is : What is the unit of data in CHGCAR ? and which option should I pick to plot isosurfaces in e/Ang³ unit.