"We have something like 8 outside taps and 3 different types of tap cover including jacket, foam box and this tap shaped one.
This seems to offer a better insulation than others to the tap, covering all parts closely. It takes a bit longer to fit but the tap can be used with the cover on (removing two plastic caps). For some of the less used taps these can stay on all year.
For some of the more frequently used taps will keep the box cover as it is fitted in seconds so easy to remove for the summer.
"This might be acceptable for a tap which receives little or no use during the winter but for anything else it is unlikely to last very long. I found the spout section hard to fit properly and hard to keep in place once fitted."