MRF Attachments forklift mounted bale spears are a popular forklift accessory utilized on farms for moving hay bales and heavy objects a snap of the finger. MRF offers four different models in two classes, class two with a rail spacing of 16″ and a class three with a rail spacing of 20″. We use the rail style which is considered the most common and installation is a quick slide on in place of the tine.