Yup, sorry. The opening in my feeder is a 1 3/4" dia. circle. I also measured the depth to the spin plate, and the plate is 1/2" below the opening in the bottom of the hopper. That's the 1 3/4" dia. opening.

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3/4 to 1 1/4 ac pond LMB, SMB, PS, BG, RES, CC, YP, Bardello BG, (RBT & Blue Tilapia - seasonal).