@User @User The _0 skywater are 1/2 strength and a few of them are also slightly narrower. The _m have matched sizes and are minimum sized. They are mostly offered in the LP. The matched size is presumably because at lower voltages the optimum energy efficient sizing turns out to be equal. There are a few _0 cells in the HD library. It’s such a small and random collection of them I can’t figure out why they even bothered. They might be from a particular project or possibly there was at some point a full set of them and a glitch prevented them from all being transferred over. I suppose this might be worth checking against the NDA’d library: sky130_fd_sc_hd/cells/a2111oi/sky130_fd_sc_hd__a2111oi_0.spice sky130_fd_sc_hd/cells/a21boi/sky130_fd_sc_hd__a21boi_0.spice sky130_fd_sc_hd/cells/and2/sky130_fd_sc_hd__and2_0.spice sky130_fd_sc_hd/cells/einvn/sky130_fd_sc_hd__einvn_0.spice sky130_fd_sc_hd/cells/o21ai/sky130_fd_sc_hd__o21ai_0.spice sky130_fd_sc_hd/cells/o311ai/sky130_fd_sc_hd__o311ai_0.spice sky130_fd_sc_hd/cells/or2/sky130_fd_sc_hd__or2_0.spice