I have a Burly Alternative hitch , from the CoOp company era, it is the QR skewer on my Rohloff..CC.
now they offer an F shaped piece, the nut or QR end holds down..
Wike, a CDN trailer seems similar, they claim compatibility.

A 2 wheel trailer usually has an elastomer rubber connection between hitch and trailer tow bar

(Your Ikea has a spring, instead)

Burly its a flat piece with a hole through it for the pin, that goes through the hitch piece above and below it.

on the Thule - Chariot hitch, the elastomer is a ball on the end of the tow arm, the hitch is a socket,
once the ball is in the socket a pin closes the opening , so the ball is held in there.

these are the 2 trailers I own...






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