This is RhB second class coach B2258, seen this century. 4

It is also known as a "4T4" as it has 4 seating bays, a toilet, then 4
more bays.  B2258 with open yellow triangles and mid-90s larger
class numerals: lettering & lining now in white, not silver.       

RhB trainsThis is one of ten centre-toilet, pre-Ew1 series of RhB 64-seat coaches numbered B2251-60.  It is shown in the condition in which the type ran after rebuilding in 1962 from open-balcony coaches first built in 1911-13.  They ran in this condition, painted in standard green livery, until fitted with DC heating connectors for working on the Bernina line in 1985-7.   From that time, re-painted in the new red livery with logo and ownership lettering, they were a common sight there during the height of the summer season, especially on the tourist trains to Alp Grüm which regularly saw three together.  Otherwise their considerable weight (20t loaded), meant they were added as and where they were needed as long as their use did not require extra motive power.  This means they were often seen in trains but only in ones and twos.  In winter they often returned to RhB metals where they can be seen in a great many photographs, their twin roof vents making them easily identifiable whether or not their central white toilet window is visible.