The Flysky FS-i6 is a very capable transmitter which can be used in a variety of applications. 6 channels give plenty of scope for use in combat robotics. The onboard display allows for many programmable tweaks, which are best discovered in the user manual or via YouTube. Requires four AA batteries, not included. This transmitter has been modified for tank-style control (left and right stick are both sprung vertically). Includes the Tronbots preferred FS-iA6b receiver.
 
Quickstart Guide
Manufacturer website
User Manual