[Yosemite Sam]

Excellent deal, you can't beat free.

Double07 is basically correct, you need a mule drive that fits your particular model tractor, the pulley mounting arms need to be straight (not bent at an angle) the pulleys should be solid, not stamped.

Not to be splitting hairs but, the yellow parts in your picture are Cub Cadet parts, they are a 3 point hitch.