New improved holder is the quality you expect from Stewart
A replacement tube for the Z Series Push or F-Series. This item is just the tube with the thread and does not include any other fitments or the bungee cord.
This umbrella holder is not designed to hold an umbrella while the cart is in motion, indeed for many users it will be too low to achieve this. It is designed as a place to put an umbrella while you take a shot.
This is also a safety precaution designed to remove the chance of the trolley becoming unstable when used in windy conditions, as a remote control machine could be a distance away from the user when in motion.