<p>The closure comprises two closure parts (9,10) which in the locking position of the fitment engage in one another. A detector such as a protruding sensor (14) detects when the casement (2) is in the frame (1) so that associated positioning means such as a rocker arm (12) moves the second closure part (10) from a retracted position into the protruding position. The rocker arm has an eccentric bearing with one lever arm shorter between the bearing and sensor than the other lever arm. Independent claim describes window with closure where the second closure part is mounted to move perpendicular to the casement.</p>
