I was very disappointed to find out these rings do not fit Gretsch Filtertrons. Having no idea that TV Jones Filtertrons have rounded edges, and Gretsch pickups are square, the pickups would not mount through. I spend hours sanding the corner to allow the pickups to slide through, and these mounts snapped in half. The shipping was so expensive, and I later found that Sweetwater has these for the same price shipped free. Not a happy experience. My feedback is for TV Jones to add to the description on this item, that it will not fit other brand Filtertrons, and even better, make the dimensions fit a Gretsch version. The TV Jones models will still fit in just fine.