Cardiff 286, KBO959, a BUT 9641T with East Lancs H40/32R bodywork. New in 1955 and only fitted with a single staircase unlike the previous batches of BUT 9641Ts.
The bus on the right is 402, 402CKG, one of the original trolleybus replacement vehicles.

Photo taken by Mike O'Sullivan, Friday 5 January 1968, Inside Roath Depot, Cardiff