This is the Traxxas Telemetry 2.0 Expander and 2.0 GPS Module Combo

Features:Telemetry Expander:
Installs quickly and easily; no parts to replace or swap
Waterproof case keeps the expander safe from the elements
Six available ports for connecting auto-detectable plug and play sensors GPS
Uses GPS and GLONASS global positioning for accurate, real-time speed
Speed readout not affected by gear ratio or tire-size
Easy plug-and-play installation; no programming required
Waterproof when installed
Automatically detected and configured by the Traxxas Link App
Compatible with the E-Revo VXL 2.0, Rustler 4X4, Unlimited Desert Racer, X-Maxx

Includes:

(1) Telemetry Expander 2.0 (#6550X)
(1) GPS Module 2.0 (#6551X)Telemetry Expander 2.0 (#6550X)
(1) Receiver data cable (optional data cables available)

Requires:
TQi radio system with Wireless Module (#6511)
TSM receiver (#6533)
Apple device running iOS 7.0 or higher, or Android-equipped device with Android 4.4 and higher
Traxxas Link App (latest version available free on Google Play and the App Store)