I've had a couple of these (watch out for tall speed bumps), happy with the fit and quality. I had my usual service garage (Simon Scott Russell) fit it for me, I don't think he used the included sealant.
https://www.ebay.co.uk/itm/292011173210?hash=item43fd38e55a:g:tmgAAOSw8w1X8spd&amdata=enc%3AAQAIAAAAwJ6hogstEQF9NzgPaUIV7YtRXePZOcO9Oz0Sfsw0098R2sAL7WIEyAM%2BmL3z0ECBC8UuJXZf2YXq45tHc8rUO9sLXhqye3pFKhpI%2BDLXq%2BZdNTsZpqkxmHeNMqD27L%2BWdUHgy6903mpYPZIPOxDaKmUDGhGmNqPcUQMxzRza%2FzjeD8YyGoqRktoIxiQOunU4GHk3nbxIzaZAYNDusxGIXk8IiiXJHqPRJ8yTVz4b5rNkqPjmmBT0AP2lPLPNX85iVg%3D%3D|tkp%3ABk9SR6jJjt3eYg
Note the item title for this link says for USA shipment, there don't seem to be any titled for UK shipment currently, but the business is UK based so maybe drop him a message if you want one.