Sorry,,,what I meant was,,,,what receiver do I need to have,,,,,sorry for the mistake...
You haven't bought the Tactic TX with the receiver? The Tactic TTX300 come with the TR326 receiver.
The Tactic TR326 has alsmot the same size than a Spectrum SRX200, the SRX200 is thicker on all his surface. The TR326 will fit in the V4 receiver box.