I just bought these about 3 weeks ago and they fit my 4 year old Genesis 3500 perfectly.  I have only used the grill a couple times since but having in tact flavor bars does make a difference in how the grill performs.   Much better than the old rotted out ones.  They were the same price as Lowe’s and free shipping.  You can find knock offs cheaper but don’t know if they would be the same quality.