The invention relates to a solar collector element having an absorber part and a tube for a heat transfer liquid connected thereto on a first side. Nucleic acid molecules encoding the antibodies of this disclosure, expression vectors, host cells and methods for expressing the antibodies of this disclosure are also provided. Global alignment markers are formed in the first substrate to enable alignment of the front gate electrode to the back gate electrode. The inner sidewall recessed portion has a plurality of recess which are adapted to engage with a peripheral projection of the upper clutch for holding the knob in place during locked and unlocked positions of the knob.