A raceway made of parallel rails permiting a “roller coaster” of tennis balls to be started by the user.
Visceral connection with the ball’s changes in motion and energy when encountering turns, hills and valleys, and final slow down section.
Made of rails separated by a snap-in device.
$200
if ball gets wet it will affect the operation.
Had a great marble raceway made by a japanese toy company (Bondai?) who made several construction toys.