SKLZ Quickswing PX4 The SKLZ Quickswing PX4 training aid will auto feed 12 baseballs or 8 softballs every 6, 8 and 10 seconds for the ultimate system for developing fast hands, sharp reaction times and solid mechanics. Four configurations: Auto-feed gravity drop, rebounder for imitation tee hitting, rebounded angled for soft toss and rebounder angled for turn around double play. QuickSwing with auto-feed drop balls on an interval you set for quick hands and reaction training. Use with practice or regulation balls. Product Dimensions: 45" to 60" H, 20" radius base, 43" barrel.