Self training: Play without training partner. unlike robot machine, this ball returned from rebound board like hit back by a real people. 2nd Generation product: Developed by professional team: a) 8 rubbers instead of 6 rubbers for covering more area. b) strong steel wheels instead of plastic. c)astringent rubbers & Glue-free sponge instead of adhesive rubbers for longer service life. Material: The wooden rebound board, the strong steel frame using the same material as professional ping-pong table to ensure perfect playing experience. Desktop rebounder will be easier to install, easier to play for beginners, support for push & block practice, more portable.. Training Video: Amazon videos included: Application Scenario, Installation Guidline, How to serve to start, Tips for Beginners, Forhand & Backhand Loop Drive and Attack Practice..please follow us to enjoy it.