I have an RU-16 receiver and was just looking at the coils sets I have on hand. Most are marked as RU-12 but three turn out to be marked for RU-17. As I understand it, the RU-12 coils will fit an RU-16 but the RU-17 coils will not fit. So if anyone needs these RU-17 coils, let me know. Wayne WB5WSV