In the campaign settings page you can choose several types of referrer hiding:
None – without hiding. The usual 302 redirect, without additional intermediate pages - the fastest one.
Meta refresh – a redirect through one intermediate page, allows you to hide the referrer in order to not show the landing or thsource. The recipient of your traffic will get the URL of that type: http://yourtracker.com/click.php instead of the referrer.
Double meta refrash – is the same, but with two intermediate pages.
Smart meta refresh – tracker detects refferer and applies meta refresh only in case if it is not empty. Otherwise there will be a usual redirect. This method allows you to reduce traffic losses, but at the same time to hide your landing.
For all types of hiding you can also select the domain that you will replace the actual referrer with. But be careful, this domain should be added into the tracker, as domain for redirects.