Bought this replacement bowl to use in my 15-year old Erva deck-mount rim, and it fits perfectly (important, as a specially-built wood mount had been made for our non-standard rail, and we didn't want to remove the attached rim). Since the old heated bowl worked great for 15 years and this looks the same, we're looking forward to many more winters of happy birds. This arrived just 2 days after ordering with free shipping!