zip kit sonnax aw5550sn aw5551sn re5f22aSonnax ZIP Kit for AW55 50SN, AW55 51SN The Sonnax Zip Kit AW55 50SN ZIP is specifically designed to address common issues in Aisin AW 55 50 51SN valve bodies by sealing critical circuit pressure losses. This kit includes uniquely engineered parts that prevent pressure loss in the main line, lockup, solenoid, and throttle signal circuits, as well as multiple circuits prone to end plug leakage. No special tools or reaming are required, making