I bought one for my el cheapo Brother and it would not work. The screw that was on the machine was not long enough, the needle would fall out so I returned it got another one (different model) with a longer screw in the packet no probs now.
My Brother is Model 2125 LS (Blue on Front) The Brother walking foot is a 5mm with the Needle screw. The one I bought first time was 7mm with no needle screw.