By the Quick-X-Change block exchange system block modules can be exchanged within seconds and the instrument adapted flexibly to changing requirements. For this purpose, in total six different mono and twin block modules are available that can replace each other. The two independent blocks of the twin block modules allow the simultaneous run of two different PCR programs and thereby help to avoid bottlenecks. The 96 well block module and the 48 well twin block module for optimization of new primer pairs are optionally available with gradient function. The FlexCycler2 provides state-of-the-art heating and cooling rates and reproducible conditions in all positions of the sample blocks with its excellent temperature uniformity. The user-friendly software concept in combination with extensive additional software options makes the FlexCycler2 the perfect system for challenging PCR applications.