Sky-Watcher SynGuider Auto-Guider. This auto guider can guide an equatorial mount without the help of a PC/Laptop, improving productivity during astro-photography sessions, helping you to obtain perfectly round stars during long exposure times. The Synguider stand-alone autoguider is supplied with guiding handset & cable, serial cable and battery pack. Requires 4 x D-Size 1.5v batteries or alternative switching AC/DC power supply meeting DC6v-12v (lower voltage recommended), 200Ma-250Ma output current, 2.1mm power jack central positive. It also features, Sony ICX404AL CCD Sensor (chip size 5.59mm X 4.68MM), 510 x 492 effective pixels, real-time star image display, standard ST-4 autoguider interface, M42 and 1.25" telescope interface and user upgradeable firmware. It will give you exposure times of 1, 2, 4, 8, 16, 32, 64, 128, 256, 512, 1024, 2048, 4096 mS.