If you are using the app, and were directed to the U.K. site possibly by opening a listing from a U.K. seller and then searching through their other items. Each time you open the app after that the address bar will show ( http.... ebay.co.uk) To get back to the U.S. site which you are on now, to search for what you want. Go to the upper right corner of this page where you see the avatar circle that is to the left of your username above. Click on it and select My ebay from the drop down list. If you are redirected to the U.K. site, use your device's browser to login to ebay.com manually with your username and password.
Once you are on that page, use the Search for anything box, enter Triple Screen computer monitor in the search box. Then select Computer/tablets & networking from the drop down list as the category. Then click on the search button.
On the page that opens there will be additional search filters in the left hand column you can use to get more relevant results. You may want to select Laptop & desktop accessories, or pick a Mfr. or screen size. Each new page will give you more filters to refine your search. look at the partial screen shot of the filters below.
