Abstract: A rotary dial telephone set has the normally opaque disc-shaped member, which closes the aperture in the top housing through which the dial passes, replaced by a transparent member behind which is held an opaque insert having indicia thereon giving both dialling numbers and related service indications in association with the finger holes in the dial. The opaque insert is held in the transparent member by a backing member. The form of numerals, i.e. Roman, Arabic, Hebrew, can readily be provided without separate disc-shaped members and similarly the service information can easily be changed without having to prepare new disc-shaped members or alternatively having to stick labels thereon.