VSL technology is based on the principle of post-tensioning where the prestress is permanently introduced into the structure after the concrete has hardened. This is achieved by the stressing of suitably arranged, high-strength prestressing tendons.

VSL post-tensioning generates favourable stress conditions in the structure, enabling efficient use of building materials while controlling deformations under service conditions.

Complying with national and international standards, they are approved in every country where the use of post-tensioning requires official certification.