does britax allow seat protector Britax - One4life® Slim All-In-One Car Seat, Mineral Gray

Britax One4Life All-in-One Car Seat grows with your child and converts to a booster, accommodating your growing child until 10 years old. With its slim design, you can easily fit 3 across in most vehicles without compromising safety and comfort.
Convertible to booster car seat grows with your child from 5 – 120 lbs and up to 63” tall.
Sleek 17.5" wide design to fit 3 across in most vehicles.
2 Layers of Side Impact Protection, an energy-absorbing shell, and foam lining surround the head, neck & torso.
Exclusive SafeCell Technology acts as a crumple zone, absorbing crash energy to help keep it away from your little one.
15-Position, quick-adjust headrest & harness to create the proper fit as your child grows.
High Strength Steel Frame reinforces the seat structure to help keep it sturdy and stabilized.
Quick-Push, 9-position recline finds the most comfortable fit for your child and the best fit for your vehicle.
Cooling Channels improve airflow to keep your child comfortable.
Easy-Read Level Indicators find the correct recline angle for your vehicle.
The removable cover is easy to remove without taking off the harness.
Dishwasher Safe cup holders twist out for easy cleaning between car rides.
1-Year Limited Warranty.