Mitel Aastra 470 System Manual page 97

Installation
1 2
Backplane (BP2U) Must be flush
4 bottom guide slots
3 fastening brackets with contact springs
3
4 top guide slots
Upper rear housing cover
Fig. 20 Proper fitting of the backplane BP2U
Aastra 470 as of R3.2 97
syd-0337/1.6 – R3.2 – 09.2014