I purchased 2 of these for a 2 sided fireplace and they really saved me a ton of money.  They look great and installed over an uneven surface - I did have to use a plumbers putty on the backside to stop the smoke. I have an uneven natural stacked stone fireplace and a custom fire surround was 4k. With a little plumbers putty and 2 of these doors the solution was under 400.00.  You can't even tell e difference.  The plumbers putty I purchased was rated for super high heat rating.