Graco TURBOBOOSTER GROW RightGuide Instruction Manual page 10

Booster Installation
Use Lap/Shoulder Belt Only
Review section 3
Position Lap Belt
Be sure the lap portion of the vehicle seat belt goes in front of
both armrests and the shoulder belt goes under the armrest
on the buckle side.
Review section 3
Highback Backless
Position Lap Belt on RightGuide™ Seat Belt Trainer
Be sure the lap portion of the vehicle seat belt goes through
both seat belt guides and the shoulder belt goes through the
seat belt guide on the buckle side.
Review section 3
RightGuide™
Seat Belt Trainer
10