For the Serpent 966 and Viper 977, Serpent introduces this new version of the front bumper, which features click type inserts on the left and right. Serpent team driver Merlin Depta came up with this idea, so you can change it fast between racing with or without inserts. It’s a few second job to insert or remove. Once inserted they click firmly in place.Running without inserts normally gives more steering, especially in high speed corners. The Aero bumper sells as set with inserts, and additional inserts are sold separately.