Tuggers are a cable strain relief gadget that has a number of uses but the main one is in protecting sockets from being damaged when a cable is accidentally ripped out.
This is the Big Tugger and it's for protecting things like power sockets by attaching it to cables sized around large mains cables or multiple cables.
Twice now I’ve had my camera monitor fall off the hot shoe adapter. Once was after a bit of camera movement but the second was when I accidentally hooked the HDMI cable and yanked it off. I’m not too concerned about the monitor but both times it ripped out the micro HDMI plug on my Sony with some considerable force. Fortunately the HDMI socket on my camera handled the extreme handling without causing any permanent damage.
There's 2 other Sizes:-
The Lil' Tugger is for protecting sockets by attaching to cables sized around hdmi or USB cables.
https://www.shapeways.com/product/PK2MNAGHH/lil-tugger-cable-strain-relief?optionId=63278672
The Regular Tugger is for protecting sockets by attaching it to cables sized around mains cable or up to a couple of HDMI or USB cables.
https://www.shapeways.com/product/ULMN5XKNE/regular-tugger-cable-strain-relief?optionId=63278650