Key Performance:
1)    Positive polarity (fluorescence increases with depolarization);
2)    >6-fold improved photostability compared to state-of-the-art eFRET GEVIs (pAce, Ace-mNeon2) under one-photon illumination;
3)    22.8% ΔF/F per action potential with SNR of ~9.78 in cultured neurons;
4)    ~1.3-fold brighter than pAce in mammalian cells;
5)    Fast kinetics (τ_on = 1.11 ± 0.18 ms; τ_off = 0.58 ± 0.08 ms);
6)    3-to >10-fold extension in functional recording duration for spike detection;
7)    Excellent membrane localization with soma-targeted variants available;
8)    Functional under scanless two-photon excitation (~10% ΔF/F with SNR 5-10).

Applications:
1)    Long-term voltage imaging in cultured neurons (>30 minutes continuous recording);
2)    Extended in vivo recordings in awake behaving mice (10-20+ minutes);
3)    Trial-based neuronal plasticity studies and skill learning experiments;
4)    Population voltage imaging with widefield microscopy;
5)    Two-photon voltage imaging in light-scattering tissues;
6)    Longitudinal studies of synaptic plasticity (LTP/LTD mechanisms);
7)    Monitoring firing pattern transitions during behavior and learning.