Custom Coaches made the body of this bus. It has 280 horsepower Scania engine. The buses were built in 2011 to 2012. The buses feature 8 wheelchair seats, a Hispacold air conditioning and a Mobitec flipdot display and THOREB controllers. However bus 2569 has an orange Hannover display board, fitted for a trial of LED displays.
In November 2017, new K310UB's were delivered. These buses are CB80 series 2's. Series 2 versions have a sleeker air conditioner and Hanover LED destination boards instead of flip dots.
In March 2019, More K310UBs started getting ordered
The buses are numbered 2378, 2404-2420, 2441-2444, 2454-2492, 2522-2535, 2546-2569 and 2886-2892. However, bus number 2527 has m/o 8542.They can be seen around the North Shore area and in the Inner West. They are at Willoughby, Randwick and Kingsgrove.
New series 2 models are at Leichhardt, Kingsgrove and Port Botany depots. However, the Series 2 models in Kingsgrove and Leichhardt were moved to transit systems in June 2018
The buses are powered by diesel. The engine is Euro 5 compliant and the length is 12.5 metres. Maximum seating capacity is 47 and the maximum standing capacity is 22. The desto controller on this bus varies, though most have a Mobitec ICU402. Note that the desto can be changed by the THOREB in any bus.
A key feature of the passenger cabin in this bus is the efficient use of space over the front wheel arch. Forward of the wheel arch is a 2-seater on the offside and a luggage space on the driver side. Behind the wheel arch are backward 2-seaters on both sides. Electrical cabinets are located over the wheel arch on both sides. There are 4 foldable wheelchair seats on each side of the bus in a 2-2 configuration.
CB80's are seen only in the TfNSW livery with a light blue chevron at the front and a white chevron followed by another light blue chevron.