Control your telescope wirelessly from your iOS or Android smartphone or tablet with the free Celestron mobile app with planetarium interface and SkyAlign technology Portable 9.25-inch Schmidt-Cassegrain optical tube with StarBright XLT optical coatings and Fastar compatibility Computerized GoTo mount with high-performance worm gears and motors for improved tracking accuracy, along with reduced gear backlash Rechargeable lithium-ion battery with enough power for 10 hours of continuous observing Improved industrial design with manual clutches and integrated carry handles, plus the added convenience of two accessory trays and a USB charge port for your smart device