One only Deltec cavity resonator or filter , having a clean out , made of copper (not aluminium) ,loss approx 1 dB ( VNA cables 0.2 db) could be extended for 6m..... or cut down to 2m.... or 70 cms or used on 88-100 Mhz band (quite heavy ) please ask for tuning freq as some wont go far into commercial fm band without small mod These are all copper $$$$ and temp compensated with invar rod and were made by an rf company , I have cheaper aluminium ones to sell but dont expect the same performance , as you know copper is the way to go for low rf loss , I purchased these ,they were not freebees as Im not in the trade ,I want to at least recoup costs . have used similar ones on Br 33 2m repeater have more of these with BNC connectors wieght is 5.5kg 110 cms long and 10cm diameter ...... freight info ! you could not build one for this price if you purchased the materials wholesale !!