NHTSA conducted extensive evaluation of the ES-2 dummy in various test configurations and concluded that the EuroSID-1 dummy’s identified deficiencies were resolved in the ES-2. However, the ES-2 back plate could hang up on some seat-back frames in side impact tests, resulting in reduced rib deflections.

Major components of the ES-2 RE kit include the Teflon cover, rib extension guide, rib extension, back plate load cell and needle roller bearing. When the rib is deformed, the rib extension travels laterally on the roller bearing. The maximum rib deflection is 58 mm. The rib module with rib extension meets the original certification requirement, and the torso mass meets ES-2 thoracic mass specifications.