These are the 36 hole single wall, rim brake compatible rims that adorn pretty much every cheap 24" kids bike.
Quick facts:
- weight: 503g;
- non-eyeletted;
- internal width: 20mm;
- external width: 26.5mm;
- will work well tubeless with ghetto tubeless method.
Taylor Wheels (out of Germany) do some reasonably priced pre-built 24" wheels with cassette hub 8-10spd compatible) using what looks to be this rim.