Why do banana plugs need these holes?

enter image description here

  • 37
    \$\begingroup\$ You can connect another banana plug in one of those holes. \$\endgroup\$ Commented Sep 7, 2020 at 10:25
  • 43
    \$\begingroup\$ They don't need it, it is a (nice and useful) feature of these particular plugs. \$\endgroup\$ Commented Sep 7, 2020 at 10:28
  • 29
    \$\begingroup\$ Yo, dawg. They heard people liked banana plugs, so they put holes in your bana plugs so you can plug a banana plug while you plug a banana plug. \$\endgroup\$
    – dim
    Commented Sep 7, 2020 at 11:28
  • 80
    \$\begingroup\$ That choice of wire colours is making me twitch... \$\endgroup\$
    – user16324
    Commented Sep 7, 2020 at 12:41
  • 5
    \$\begingroup\$ It's called a bananana plug. \$\endgroup\$ Commented Sep 8, 2020 at 4:32

2 Answers 2


Your banana plugs have holes so that the plugs can act as banana jacks.

You plug one banana plug into the plug panel of, say, a power supply. You can then plug another banana plug into the first plug.

It's a helpful feature for making multiple connections with banana plugs.

  • 14
    \$\begingroup\$ "Jack" being "socket" in British English. \$\endgroup\$ Commented Sep 8, 2020 at 8:29

Does this banana plug picture help you understand why: -

enter image description here

You can get different variants too: -

enter image description here

And end-stacking types: -

enter image description here

  • 1
    \$\begingroup\$ With 4 of them and a little skill you can (probably) get a mechanically almost locked 4 wire connection :-). \$\endgroup\$
    – Russell McMahon
    Commented Sep 9, 2020 at 3:24
  • 2
    \$\begingroup\$ @RussellMcMahon it is not that difficult actually, it is not actually locked as it might seem. You just make two couples and then mate those. \$\endgroup\$ Commented Sep 9, 2020 at 6:33
  • \$\begingroup\$ @VladimirCravero Yes - I visualised how to put it together. Past experience (not with banana plugs) suggetss it MAY require "wriggling it all together" . Not hard but sometimes 3 hands needed. I'll try it some time :-) \$\endgroup\$
    – Russell McMahon
    Commented Sep 9, 2020 at 8:52
  • \$\begingroup\$ If you have banana banana cables long enough, you can build yourself a nice pendant. \$\endgroup\$ Commented Sep 9, 2020 at 13:01
  • \$\begingroup\$ Banana #1 is also known as an insulated banana. The barely visible plastic around the pin helps against accidental short-circuits, particularly useful when working with mains voltage. This particular one probably has a retractable sheet, there are also plugs with fixed sheets. Those are less-stackable but even more safe. \$\endgroup\$
    – Mast
    Commented Sep 9, 2020 at 13:12

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