Pre-supernova CSM profiles of the number density (n; panel a), the flow speed (u; in panel b), the thermal pressure (P; panel c), and the temperature (T; panel d) at 8.64 million years after the ZAMS stage for the 20M_⊙ progenitor (on the left) and at 3.95 million years for the 60M_⊙ progenitor after the ZAMS stage (on the right). The right panels are reproduced from Das et al. (2022). Vertical grey lines mark the boundaries of specific regions. For the 20M_⊙ progenitor, these are the free RSG stellar wind (region 1), piled-up RSG wind (region 2), shocked MS wind (region 3), shocked ISM (region 4), and ISM (region 5). The RSG shell indicates the accumulation of decelerated, freely expanding RSG wind; R_RSG denotes the transition between RSG and MS wind; and CD represents the contact discontinuity between shocked wind and the ISM. For the 60M_⊙ progenitor, we distinguish the free stellar wind (region 1), the shocked LBV and WR wind (region 2), the shocked MS wind (region 3), the ISM (region 4), and the ambient ISM (region 5). The term R_WT is the radius of wind termination shock, LBV shell denotes the dense shell created by the interaction between LBV wind and WR wind, and CD represents the contact discontinuity between the shocked wind and shocked ISM.