THIS IS THE NEWEST VERSION OF THE KNOCKOUT SERIES LATE MODEL/MIDWEST MODIFIED CHASSIS. 3MM CARBON MATERIAL. SHAPE CHANGES AND TWO SERVO LOCATIONS MAKE THIS THE MOST ADJUSTABLE FOR DIFFERENT TRACK CONDITIONS. NEW LENGTH WHEELBASE OPTIONS OFFER SHORTER THAN THE PREVIOUS CHASSIS AND KEEPING THE LONG SETTING IN PLACE. NEW STYLE BATTERY HOLD DOWN PATTERN ALLOWS FOR A NEW DESIGN HOLD USING EITHER VELCRO OR TWIST TABS TO HOLD THE BATTERY IN PLACE. ALSO CAN BE USED WITH THE NEW AE B7 BATTERY HOLD DOWNS AS WELL IF YOU PREFER.