SkyBT Bluetooth Wireless Telescope Controller Serial (RS232) to Bluetooth Adapter for Telescope Control on Android Phones/Tablets Running SkySafari. Compact, Stable and Durable for Astronomy Field Use & Easy to Pair/Connect and Begin Controlling Telescopes in Seconds. SkyBT Requires a Telescope-specific RS232-to-Serial Cable Available Here: http://store.simcur.com/cable. Not Compatible with New Celestron USB Hand Controllers. 8-10 Hours of Battery Life (AAA; Alkaline or Rechargeable) During Field Use & Great Usable Range of ~100 Meters / 325 Feet.