These telescopic whips are used to make our homebrew Buddipole or Buddistick antennas. Extended length is 72" and collapsed length is 13". The base is 1/4" x 20 threads. We now are double-crimping the bases for added durability.
We also make a knurled base sleeve which prevents the base from working loose over time, especially if the antenna is used in windy environments and/or in a horizontal position. These knurled sleeves have the added advantage of making it easier and quicker to thread the antenna into place.
Stock up on these for your next antenna project!