This is the Traxxas Link TQi Wireless Module.
FEATURES: For use with the Traxxas Link app and TQi radio system
Compatible with iPhone (4S or later)
iPad (3rd gen and later)
iPod touch (5th gen and later)
Allows driver to view real time telemetry with optional sensors
(sensors not included)
INCLUDES: Traxxas Link TQi Wireless Module
1.5mm Hex Wrench
1.5x5mm Hex Head Screw
SPECS: Dimensions: 1.2 x 1.8 x 0.42" (31.5 x 46.8 x 10.8mm)
Weight: 0.26oz (7.5g)
BOX DIMENSIONS: 3.75" W. X 1.63" H. X 4.13" L.
BOX WEIGHT: .12 LBS.