Datacolor Spyderlenscal SLC100 Lens Calibration System, Black/White Spyderlenscal provides a fast, reliable method of measuring the focus performance on your camera and lens combinations. It allows photographers to obtain razor-sharp focusing or check to see that their lenses are working at their peak performance. This device is compact, lightweight and durable, with integrated level and tri-pod mount. Includes Datacolor Spyderlenscal and quick start guide.