10BASE5 Thick Ethernet Cable, 10Mbit/sec.

In the 1980s and early 1990's, Ethernet became more popular and provided a much faster data transmission rate.  This cable is one of the first ethernet cables from 1983, a thick, bulky affair.  Computers were attached via "Vampire Taps" which were  connectors screwed straight through the shielding of the cable.

See more at:

https://en.wikipedia.org/wiki/Vampire_tap   and    https://en.wikipedia.org/wiki/10BASE5