THEY ARE NEW I USE THEM IN MY PERAZZI THEY ARE AFTERMARKET NUMBERED LIKE FACTORY TUBES THE NUMBER X 4 IS THE CHOKE SIZE A NUMBER 7 X 4 IS A 28 TH IM CHOKE THERE IS A 4 TWO 5S THREE 7S ONE 8 AND ONE 9 SHIPPING IS 8.00
They look like 18.4 and generation 2. I cannot tell for sure But they look just like the ones i have.
They are type 3 threads at the bottom type 2 have threads at top it look like they were purchased from a guy in Oregon on Ebay Sgoose