The bulbs were a little shorter (3/4-1 inch) than the originals as I noticed some other people were saying the same thing, but this doesn't affect performance the heaters. in general it works like new again when i had blown 2 out of 4 bulbs it sure worked weird, just warmed up for a few minutes then the fan went on and off every few minutes. Now it gets nice and hot and continues to work until the temperature in the room becomes. So there are no complaints!