Britax Safe'n'Sound Instructions For Installation & Use page 22

INSTALLING THE BASE
Always leave a
rearward slope angle of
approximately 10° to 15°
10° to 15°
ROAD
MANUAL PACKING
The angle may also be altered by placing a firm packing between the seat and the
underside of the base (packing can be a firmly rolled up towel)
For some vehicles with flat seats, packing may be required at the front edge of the base
to get some recline. The stabilising bar does not need to touch the car's seat back but
should be close.
Always leave a rearward slope angle of approximately 10° to 15°
Packing
10° to 15°
ROAD
22
Instructions for Installation & Use