• Airkey Retro series transmitters have been superceded by the Airkey 4th Generation series. 
•  Airkey 4th Generation transmitters are compatible and suitable for replacement of Models AKTX2, AKTX4 and AKTX4-W26 from the  Retro Series
• Please see Below link to see the Airkey 4th Generation product Range 

  “Click Here” to see  “Airkey 4th Generation Transmitters”