The Britax SecureGuard clip is an added anti-submarining safety feature available for the Britax Frontier and Britax Frontier 85, when used as belt-positioning boosters. Exclusive to Britax, SecureGuard works with your vehicle safety belt to prevent your child from sliding under the lap belt (submarining) during impact, reducing the risk of abdominal injury.
The SecureGuard clip slides over the lap belt portion of your vehicle safety belt to keep the lap belt properly positioned over your child's hips/upper thighs at all times, even upon impact of a crash. Essentially, the SecureGuard clip creates a fourth anchor point, making the traditional 3-point lap and shoulder seatbelt system a 4-point restraint.
Note: SecureGuard is also featured on the Britax Parkway SG belt-positioning booster. However, it comes included with the Parkway SG and is sold as a separate accessory for the Frontier and Frontier 85.