The chassis used was the Daimler Fleetline which later became the Leyland Fleetline.
Engines used were the Gardner 6LXB, Leyland O.680, Leyland O.690 and Rolls Royce Eagle.
The bodywork was by Park Royal or MCW.
The DMS was the first purpose built, one person operated (opo), double deck
bus bought by London Transport. Earlier Daimler Fleetlines (XF), Leyland
Atlanteans (XA) and the front entrance Routemaster (FRM) were bought before one
person operation of double deckers was allowed, they were subsequently used for
opo when the law was changed. The DMS had a split front entrance offering driver
service or automatic fare collection (afc) and a centre exit, similar to that
already in use on the SMS single deckers. A periscope was provided so the driver
could view the upper deck.
DMS means DaiMler Standee, London Transport refered to standing passengers as standees and 21 were allowed on a DMS.