The Fence Trainer is simply the best training aid to practice the extension and swing needed for serving. Use it alone or set it up as a "station" in group lessons or team practices. The new and improved Fence Trainer sets up in seconds and is very easy to use. Six height adapters adjust the Fence Trainer to players ranging in height from about 4 feet 6 inches to 6 feet tall. The unit is designed to quickly hook over any 10-foot fence and attach easily with or without windscreens.