This invention concerns improved watch band adjustment unit, comprising a fixing unit, fixing pieces, rotating pieces on the left and right sides, and a passing fixing component. The fixing unit, fixing pieces, and rotating pieces form a first locking channel; the fixing pieces and rotating pieces form a second locking channel, with a locking limit portion. The fixing component is an interference fit rod or screw. When the rotating pieces are pulled and rotated, they compress an elastic member and disengage from the first fixing rod, allowing the adjacent adjustment unit to be mounted or dismounted, enabling quick assembly and reducing production costs.

The wearable device may include a first aligned link coupled to a second aligned link, with a dome cover therebetween to conceal a linking between the first aligned link and the second aligned link. The first aligned link and the second aligned link may be movable relative to each other and with a constriction of a predetermined angle of the movement between the first aligned link and the second aligned link.

A band configured to wrap around and be secured to an object includes at least three members pivotably connected to one another so as to be pivotable between an open position and a closed position, the first member including an outwardly disposed face defining an imaginary plane and each of the second and third members including an actuator prong that extends outwardly beyond the imaginary plane when in the open position and that is retracted to no longer extend outwardly beyond the imaginary plane when in the closed position. Movement of the object into contact with the first member so as to exert actuation forces toward the outwardly disposed face when the actuator prongs are in contact with a surface causes the second and third members to move from the open position to the closed position due to forces created between the actuator prongs and the surface.