MEUS Racing 4WS Four-Wheel Steering Control Line Upgrades with 4WS Control Board, and Servo Control Line for 4WS car models such as 1/10 SCX10, TRX-4, 1/8 Redcat Gen, 1/24 SCX24, and 1/18 TX4M, etc. Key Features: Enable four-wheel steering to bring your crawler to the next level without a high-cost transmitter. Not compatible with the stock TRX4M transmitter, the transmitter must have CH2 and CH3. Four optional modes: 1. Front wheel steering (rear servo locked), 2. Rear wheel steering (front servo locked), 3. Four-wheel steering(same direction), 4. Four-wheel steering(opposite direction) Two methods to switch among different modes:(1) Plug in CH1 and CH3, press CH3 button to switch modes (2) Plug in CH1 and CH2, keep the throttle at the middle position, and make sure there is a signal at CH2. Fast-rotate (1-1.5s) the wheel clockwise or counter-clockwise three times to switch modes, which means you can’t switch modes while the crawler is running, and it also prevents you from misoperation while running. CH1: Black; CH:2 White; CH3: Red. Package List: 1 × 4WS cable