Alexander Dennis 3-axle double-deck bus with 'facelift' Enviro500 bodywork 3 doors and twin staircase (scale 1/76 - 12.5 metre length) The bus - SG Bus operate 50 buses of this type, featuring three doors and two staircases, which were progressively delivered to Singapore from May 2021, with the first unit being registered in September 2021. The 50 buses are registered as SG6333M - SG6382X. SMRT operate five of these buses, Tower Transit operate 20 and SBS Transit operate 25. The buses made their revenue service debut on 26 October 2021, operating on services 190 and 974. The above information has been extracted from the excellent LandTransportGuru website.