This paper will present the results from a series of HYGE sled tests that were conducted by the National Highway Safety Administration (NHTSA) to evaluate aftermarket devices designed to reposition the shoulder belt to improve fit/comfort. Three types of devices were tested using the 3- and 6-year-old and percentile female dummies. Baseline (no device) tests were also conducted. Additionally, tests comparing the use of a belt positioning booster seat with and without one of the devices were also conducted.