One is for 7mm and one is for 5mm you buy your foot based on the max stitch width of your machine the 7mm I think is SA140 and I think your machine is 7mm
http://www.brother-usa.com/homesewin...a#.UJXmHcWulOg
just go to accessories and it tells you what feet are compatible all 7mm feet should be compatible, but may not be listed under accessories for your model even if they work.
SA 140 is for 7mm machines which yours is. You can email brother about it and they will reply withing a day with the answer to which fits you machine but. Most machines either take SA 107 which is 5mm or SA140 which is 7mm then there are 2 more models which only belong to specialty machines like the PQ1500S