Ever wondered what is within these buggers, well heres a couple dissected.
Two models of Andrew surge arrestors, on the left is a APTDC-BDFDM-DB which is described by Andrew as a, Arrestor Plus® LTE Band Quarterwave dc Passing Surge Arrestor (T-shaped), 6982700 MHz.
And the one on the right is a APGMB-BNFNM-090 which is described as a Arrestor Plus® Gas Tube Surge Arrestor (90 V), 452170 MHz, with interface types N Female Bulkhead and N Male.
Upon removing the T from the APTDC, one finds within the T are two components, a standard 350 volt gas tube and the slug, which on one end connects to the pass-through within the body while the other end is against a spring loaded gas tube in the cap.