This can either be SBS 1757U or SBS 1887C or any cameo. I did
see SBS 1820U, SBS 1850H, SBS 1868H and SBS 1884K at Hougang
Interchange yesterday, so it must be any of the three buses
mentioned above since they did not appear yesterday.
So next time when you are sitting near an emergency exit door, be
more aware of your surroundings.