The Ford GTF Is a lawn tractor built by the Ford Motors Company in the 80's. The are substantiall large, roughly the size of a modern Lawn Tractor. Their build is much more square and much lower to the ground then a modern lawn tractor, and is arguably wider. These lawn tractors seem to be somewhat more prone to ruin and malfunction than other Ford products, though this is a completely metal design.
It is theorized though not proven that these had a small disk that could be bought with or separate of the lawn tractor itself though the disk is too light and small to plow through tough soil without extra weight, which could possibly overpower the lawn tractor itself.
The Ford GTF
The small disk that possibly came with the Ford GTF