When you think of companies that make wearable tech, Jaguar doesn’t immediately leap to mind.

For the new sport SUV, the F-Pace, the car manufacturer has created a rather novel wearable called the Activity Key.

The Activity Key is a R4 300 wristband with one function: it unlocks and locks your car. This means you can access or lock your car when lugging around a key fob just wouldn’t be practical.

If you’re a fan of the outdoors, the Activity Key comes in pretty handy – especially if you decide to go swimming, or surfing or mountain biking and you’re worried about losing your key fob. The Activity Key is waterproof and Jaguar made sure to inform us that it’s ‘proof’ and not ‘resistant’ up to a whopping 20 metres.

To use it all you need to do is leave your car (leaving the key fob inside), and then you can lock it by holding the band against the ‘J’ of the Jaguar logo on the back of the car. This both locks the car and deactivates the key fob. When you’re done with your extreme sports, press the boot release, hold the band against the ‘J’ again, and the car will unlock.

The technology here is simply an RFID tag embedded in waterproof rubber to keep everything dry.

Looking past the price, there are some other caveats to keep in mind. For example, you can only unlock the car if it was originally locked with the Activity Key. Locking it through the key fob or app will leave the wearable unable to do anything.

While the car’s owner can synch their car up with eight of the bands (or seven family/friends who you don’t mind blowing a lot of money on), the car can only be unlocked by the band that was used to lock it.

If you lock the car and then lose the band (or a shark steals it and your arm) you’ll need to get your Jaguar back to the dealership so they can unlock it.

For our demo, we were only shown a plain black variant, but we’ve been told more colours are on the way. It’s rather bulky but it’s surprisingly light and won’t get in the way when you’re enjoying your preferred extreme sport.

The Activity Key is very much a one trick pony for an extremely specific market. Even if this appeals to you, don’t forget that massive price-tag; R4 300 could buy you most wearables or trackers which have many more features.

That being said, if you’re in the market for a brand new Jaguar we assume money isn’t much of an obstacle.