Dometic's aluminum roller tubes are made to fit most standard size patio awnings.
This roller tube will measure approximately 18' 6" in length (+/- 5/16") and is made to fit an awning that measures 19' from center of the left hand awning arm to center of the right hand awning arm.
The diameter of this roller tube is approximately 3-1/2" (+/- 1/8") and has 3 channels for the poly cords that are sewn into your existing awning fabric and/or LED light strips that you might also have already on your existing awning assembly.
NOTE: If you are not sure if this roller tube is the correct one for you, you will need to take a photo of the manufacturer's information off of the label on your existing roller tube (Model #, Product #, SKU, etc...) and email us that information so we can verify what size you will need to order. If the label is not there anymore or if it is not legible, then you will need to contact Dometic directly at 800-544-4881 for further assistance.