What to put after taking off rear stabilisers from child bicyle? I removed rear stabilisers from my 9y old daughter's bike a while ago, but I lost the little pieces that are supposed to replace the stabilisers.

Today I don't even remember what they look like. Any idea what these pieces are, meaning their name &amp; specs (if they're standard) so I can maybe order them on Amazon?
You want a washer and a nut on each side. Take it down to your local bike shop or hardware store to find the right size.  Any other parts that were on there were specifically on there for the stabilizers (training wheels).  Training wheels usually have a retaining mechanism that stops them from twisting, but this piece isn't needed once you remove the training wheels.