Great machine for tennis training. Throws balls with plenty of speed from base line or behind. Dual motor makes adjusting for backspin or topspin easy and handy left/right and up/down oscillation. App is easy to use and gives good stats on balls hit. I would recommend this machine. (rollers were a bit slick at the start. Tilting rollers to maximum down travel would be a good idea first time out of the box, took a bit to get the first balls to feed, then it has been fine since. Would recommend only feeding one or two balls into the hopper initially on first run out of the box until the wheels are operating correctly)