Celestron NexStar Evolution Series 6" Telescope + Celestron Case or NexStar 4/5/6 & 8" Optical Tube Assemblies Control your telescope wirelessly from your iOS or Android smartphone or tablet with the free Celestron mobile app Compact, portable 6-inch Schmidt-Cassegrain optical tube with StarBright XLT optical coatings and Fastar compatibility Computerized GoTo mount with high-performance worm gears and motors for improvedtracking 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