Abstract: A security device for installation adjacent a sliding door or window to detect movement thereof. A pair of telescopically constructed tubes include a plurality of batteries connected together to an audio alarm and visual alarm. A pair of movable contacts are disposed between the source of electrical power and the alarms and are movable together to complete the circuit by a depressible switch activated by the sliding door or window. The switch includes a rigid member slidably mounted to the tube with a threaded member fixed to the rigid member and extending towards the movable contacts. An adjustable nut threaded to the end of the threaded member allows for presetting of the space between the switch and the contacts thereby adjusting the sensitivity of the switch and security device to the movement of the sliding door or window.