Traxxas 1/10 Slash 4x4 Ultimate TEMPERATURE & RPM TELEMETRY SENSOR Speed TQi These Telemetry Sensors Are To Be Used With The Traxxas TQi Radio System With The iPhone Docking Base Temperature and Voltage Telemetry Sensor Long (Part # 6521) Plug Grey Plug Into V/T Slot On Receiver (Traxxas Part # 6518) Red Plug Will Be Used To Plug In The Power Tap From The ESC NOTE: If You Do Not Have A Power Tap On Your ESC, You Will Need To Order The Traxxas Power Tap, Part # 6541 (We Do Not Carry This Power Tap) About 7.5" Long (190mm) Temperature Telemetry Sensor Mount Includes: Temperature & Voltage Sensor, Long (Part # 6521) Temperature Sensor Mount (Part # 6535) RPM Sensor, Long 3x4mm BCS (2) (Part # 6520) Telemetry Trigger Magnet Holders/Spur Gear (Part # 6538) Part number(s) included (in factory packaging): 6521 6535 6520 6538