The price remains unchanged. If you use ladder line, this is the perfect center insulator for your project. It properly supports and provides strain relief for your ladder line. Full instructions are included. After you use one of these, you'll never use one of those home-made things again.
Ribs are spiral cut for winding loading coils, etc.
Used as a strain-insulator, this insulator is excellent for heavy wire antennas. They are NOT suitable for towers, but are OK for masts, verticals, etc. We use them on wire antennas because they can be installed in the middle of a wire without removing the end-insulators and threading them on. Get a couple of dozen before someone figures out what these things should really cost. These are the insulators we use in our antenna systems.