The last 15 O405 chassis acquired by then Trans Island Bus Services (TIBS) received the CR221 bodywork from Volgren Australia and entered service in 1999. Also the updated Mark II type, it was powered by the supercharged Mercedes Benz OM447hA engine (11,967cc) that is Euro I compliant, fitted with the 4-speed ZF4HP500 automatic transmission, and overhead air-conditioning from Denso of Japan.

The EDS was supplied by Lawo Luminator Europa (now LAWO) of the Aluma make, which consists of LED lighting behind each individual flip-dot that would be clearly illuminated at night. These buses carried the standard green interior scheme Trans-Island used in that era with the newer and thicker green leather seat covers (as compared to other OAC O405s and O405Gs which used fabric seat covers).

Despite the small fleet, the O405 Volgren in its heyday can be spotted running in most SMRT services from time to time. A majority of them are registered with the Malaysian authorities from 2011 onwards for cross-border operation in service 950 between Woodlands and Malaysia. By the end of 2014, a majority of these units were relegated to serve as training buses. All units were retired by February 2017, marking an end to the non-WAB rigid single-decker buses in SMRT Buses' fleet.