I just had a Trail Air installed last week . I had thought about on line purchase and save a little $$$$$. I thought I would go to my local RV shop and I was able to see what was involved to install one. Thank God I was able to see what it took to install one ,and the equipment and heavy duty tools it took to do the job. Two men a hydraulic hoist to lift the 200lb unit and hold it in place while the bolt holes were lined up. Then they also needed to locate the electrical box and the break away. I gladly paid the installation fee at the shop. My total bill was $ 1,385 well spent $$$.