Product review (1 stars): actual measurement is 7/32 x 3 1/2 x 2 1/2
The fan listed measurement, 3 1/2" (outside diameter) and 2 1/2" (length) is good but the rod bore at 1/4" diameter is wrong. If the motor fan rod is 1/4" diameter it will break the fan if you force it in - mine did. What I found out later is that the rod bore opening starts as 1/4" diameter for about 1/8" deep but then the rest of the length rod bore opening is actually 7/32". I will contact the seller then update this review.