The ring has a trapezoidal shape and is 4-1/2 inches wide at its longest point

From Tech Data Sheet

Motor Type: Split-Phase

35 GPM) - FSD: Foam (Container By Others) - HD1: DC Motor 120v/60hz

): 8 1/2 in

Century AO Smith 484 Blower Motor, 1/15 HP, Split-Phase, 1550 RPM, 115V Mount Type-Semi-Recessed Mount The ring has a trapezoidalCross Reference: Jenn Air Item: Direct Drive Blower Motor, Motor Type: Split Phase, HP: 1 15, Nameplate RPM: 1550, Voltage: 115, Enclosure: Open, Rotation: CCW, Hz: 60, Phase: 1, Speeds: 1, Bearings: Sleeve, Shaft Number: 1, Shaft Length: 2. 5", Shaft Dia.: 0. 375", Thermal Protection: Yes, Cooling: Air Over.