Just to add Tiny means its a Auto clutch. (Rotax Max) Like you get on a scooter where the engine revs increasing throws the clutch shoes out to transmit the drive.

IMO these are a much better one to get for a toy as they are sufficiently fast and you can race them if you want. Ignore anything with a shifter And definetly ignore push start arrangement karts they are a pain for novices.

Heres a pic of the Tony Kart Frame Rotax Max I helped run last year.