Explore the Universe and control your NexStar Evolution telescope with the free Celestron SkyPortal app for iOS and Android! Compact, portable 8-inch Schmidt-Cassegrain optical tube with StarBright XLT optical coatings and Fastar compatibility Computerized GoTo mount with high-performance brass 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