Abstract: A wristband for mounting a wearable device having a back case around a user's wrist to place the back case in contact with the user's skin. The wristband has a flexible layer with adjusting elements for adjusting the wristband to the user's wrist, coupling elements for coupling the flexible layer to the back case, and a buckle coupled to an end of the flexible layer. The buckle has a frame and a pivoting prong coupled to the frame for selective engagement with the adjusting elements. A tightening mechanism is arranged in the frame for obtaining a predefined adjustment of the wristband band around the user's wrist to thereby increase the contact of the back case with the user's skin.

Abstract: A wrist-watch back case for replacing existing back case of a timekeeping device or to be attached thereto is provided. The back case comprises a casing comprising a bottom wall and a side wall thereby defining an inner empty space, at least five openings at the bottom wall, an optoelectronic board, at least two paired radiation sources and at least one radiation detector. Methods for measuring biomarkers, systems and a watchband are also provided.

Abstract: A wrist-watch back case for replacing existing back case of a timekeeping device or to be attached thereto is provided. The back case comprises a casing comprising a bottom wall and a side wall thereby defining an inner empty space, at least five openings at the bottom wall, an optoelectronic board, at least two paired radiation sources and at least one radiation detector. Methods for measuring biomarkers, systems and a watchband are also provided.