The difference is that the Pre-Selector is a very fast, easy-to-fill tool that you want to use on applicants who qualify because of their resume, and you are interested to invite them for a first interview. When you get the Pre-Selector test results, you can use them to challenge the candidate during the 1st interview.
The Recru-Tec test is a very deep, precise personality analysis which evaluates if the applicant has the right personality traits for the position. We usually recommend that you ask applicants who have passed the first interview, to fill the Recru-Tec test. In other words, we do NOT recommend that you use the Recru-Tect test on applicants who did not pass the 1st interview. When you get the test results, you can use them to challenge the candidate during the second interview.