EVVA combined the ESKIS system developed by Zeiss-Ikon with the award-winning GPI system. It was one of the first times that GPI's mechanical security was brought together with the electronic benefits of ESKIS, such as access documentation and fast changes to authorisations. The required e-cylinder was designed on the basis of tried and tested GPI technology. As an alternative to ESKIS, EVVA offered durable key tags, which contained ID information, known as EIS – Electronic Identification System.