30mm x 15mm Pattress Adaptor - White
The Pattress Adaptor links from 30x15mm lengths into 25x16mm knock-outs (as appear on most pattress bases).
Note Pic on left shows the different style shoulders on each side.
The visible piece is gently rounded to make it a perfect accessory for 30x15mm lengths going across a ceiling and along to a pattress base (for ceiling rose). .. the most popular application.