LE units due to respecified welding specifications for the turbocharger oil supply pipe. Singapore SMRT Buses SMRT Buses had taken delivery of 134 Mercedes-Benz OC500LEs for fleet replacement and expansion. These buses feature bodywork built by Gemilang Coachworks of Malaysia and assembled by Thonburi Busbody Limited of Thailand, with a CapaCity licensed front from Mercedes-Benz, engines that meet Euro V emissions standards and are SMRT's first wheelchair accessible buses (WABs). They were the first to feature voice announcement system, with announcements similar to the ones used on the MRT. They are also the first buses in South-East Asia to be fitted with a Euro V engine. The last bus to be registered, SMB134H, was registered on 1 October 2009. Demonstrator The first OC500LE took part in the launch of SMRT's Go Green event on 30 April 2008. The bus was later registered as SMB1H and initially entered revenue service on Service 190 on 29 June 2008. It was later redeployed to operate on Service 172, only half a year into service. It is currently used as a Kranji Bus Depot (KJDEP) training bus with a new design of EZ-Link card readers installed. First production batch The batch were registered in the ranges of SMB2E to SMB67T. The first few units of this batch were put to service from 22 September 2008 onwards. Second production batch The second production batch featured many more differences as compared to its first batch counterparts, most notably its interior. Blue as well as purple colour schemes were used on the seats in contrast to the first batch's corporate colour seats. Stickers greeting onboard passengers can be found at the front and the rear of the bus. A blue tint situated on the top of the windscreen below the Electronic Destination System reduces glare from the sun, and more grab poles and aircon outlets were added at the last few rows of seats. They were registered from SMB68R till SMB134H. The first few units commenced passenger service on 1 July 2009, almost a year to the day the first unit of the OC500LE (SMB1H) made its first trip. They can be mostly found on WAB-certified services, similar to the first production batch. SMB91Y is installed with Mobitec MobiLED EDS replacing its original EDS, LAWO BENEFIT EDS due to accident in January 2012. Tower Transit In March 2021, Tower Transit took over 1 OC500LE from SMRT Buses