Abstract: In order to provide designs of corner and junction assemblies for service provision ducting which are simple to construct and do not require a large number of components, there is provided an internal angle cover part 22, 28, 31, an external angle cover part 21 and a straight wall cover part 36. These can be combined together to form a flat bend (FIG. 4), a cross-over (FIG. 5) or a flat T (FIG. 6). Each cover part comprises a cover surface 22, 23, 28, 35 which extends up to, but no further than the centre line of the respective section of service provision ducting.