*PLUMBERSSTOCK EXPERT* responded:
Hi, good day! Thank you for posting an inquiry on our website. This Metal-Fab 12MC vent cap can be used as cap for your gas fireplace but it's more common to use a 4-inch flu/pipe instead of the 12". Please double check the vent size of your fireplace before ordering. If it is indeed 4", the Metal-Fab 4MCHP vent cap will do. If you're ready to place an order, simply click on Add to Cart and enter your information in the required fields. For your question about return policy, please refer to this Return Policy Page. We hope that this helps. Enjoy shopping at PlumbersStock.com! Have a great day.