"Harness adjustment" refers to making necessary changes or modifications to a harness, usually a safety harness, to ensure that it fits an individual properly and securely. Full definition
A one - pull harness adjustment ensures its correct tension. (kiddies-kingdom.com)
If you are buying a booster car seat, see that it comes with a buckle release and upfront harness adjustment. (babyseats.reviews)
Five strap positions means that the harness can be adjusted for growing children and the easy access up - front harness adjustment makes it easy to adjust the harness for a snug fit. (mommystroller.com)