Viper Responder 2-way Car Alarm Security System with Keyless Entry, Remote Start and Squash Air Fresheners Viper is proud to introduce our most affordable 2-Way security system, which will wrap your vehicle in protection, with the most sophisticated electronic technologies available today, including the Stinger DoubleGuard shock sensor, Revenger six-tone siren and Failsafe Starter Kill. 2-way confirmation through Brilliant OLED Display On board remote start relays Responder 2-Way Security and Remote Start System Viper SmartStart compatible