Ride on lawnmower wheels with 21-10-8 quad bike tyres. Will fit most ride on mower transaxles with the 19mm 3/4 shaft size bought these for my ride or mower years ago but never used them could be useful for many products trailers called bikes go-karts et cetera.  Condition is used signs of wear and tear rust spots on rims. Tires are old but not cracked. Haven’t tried putting air in either of them they are currently flat. 
eBay