Cartman is correct older PTX transponders can still be sent to us for a *trade in upgrade*, you get back a new PTX (NS) transponder for 1/2 price plus shipping. We also have a *special* offer (discount DISC1014 incl free shipping) you can get a new transponder without having to send your old one. Our trade in offer is also available for AMBrc and RC4 transponders. It's OK to trade in old transponders in any condition including ones that are not working, with broken leads or damaged cases. Note, the new PTX (NS) 'new system' spec type flash twice when powered up, the old type don't flash. FAQ/help about trade in's/upgrades and offers link: http://bitly.com/mrt-help or for more information send me an email: [email protected]