I think it started at the xseries tractors like the 485. There were 2 hitches available for them. I had the limited cat 1 on an x475. The lift arms were flared out to accept the 26" width of cat 1 implements. The limited cat 1 means you really have to stick to the compact attachments that are designed for the SCUTs like the 2305. Actually the large JD GT's are pretty much the same size as the 2305 and even a wee bit larger than the Kubota BX tractors.