Multi-band prompt emission light curve of GRB 210905A. The light curve of GRB 210905A as seen by Swift/BAT (15 − 350 keV, 6 s binning, count rate/50, cyan), Konus-Wind (20 − 400 keV, 5.888 s binning, count rate+200, green points), Swift/XRT (0.3 − 10 keV, count rate+400, grey points) and REM (flux density+200 in units of 0.1 Jy, red points). The evolution of the gamma-ray emission is highlighted with a black smoothed spline to guide the eye. The intervals corresponding to the three main and two smaller pulses are highlighted by turquoise- and grey-shaded areas, respectively.