Optare Solo

The Optare Solo is a low-floor single decker bus made by Optare in 2 generations since 1978 and it has different lengths. 
Slimline.
A narrow version called the "Slimline" was launched in 2004
SE.
A short version called the "SE" was launched in 2006
SE.
An Electric version called the "EV" was launched in 2009
SR.
A second generation version called the "SR" was launched in 2007 and replaced the first generation Solo
Hybrid.
A First and Second diesel-electric hybrid Solo was also launched.