Bus 621 is a Scania K360UA 6×2/2 articulated bus with a Volgren Optimus body. It was delivered on 30 June 2017 and entered service at Belconnen Depot on 27 July 2017.
It was ordered as an extension to the Scania contract which commenced with Bus 539 in 2014. Since Transport Canberra wanted an alternative to the Custom CB80, Volgren was selected to build the body.
Currently Bus 621 is unique within the ACTION fleet – it is the sole Volgren bodied bus, the only Euro VI specification K360UA and the first articulated bus in the Transport Canberra blue livery.