One continuous circle of sterling silver wire, folded back on itself and threaded through a silver loop at each end.
That loop is the thing. It lets the bangle open wider, to pass over the hand and close back down onto the wrist. No clasp. No hinge. Just the wire doing exactly what it was made to do.
The mechanism is quiet. The result is a bangle that sits close, moves with you, and comes off without a fight.
Made by hand, one at a time, in my studio in the Manawatu.