We won’t know the final Apple Watch details until the big event next week, but that hasn’t stopped third-party companies from building accessories for the new smartwatch. Now, one firm says it can double the device’s battery life, though it won’t come cheap.
Reserve Strap is available for pre-order now starting at $249—just $100 less than the cheapest version of the actual Apple Watch. The third-party strap features a pair of lithium batteries that sit on either side of the watch itself. The charging works using the MagSafe technology embedded in the back of the smartwatch, and should extend the device’s battery by as much as 125 percent.
This isn’t the first Apple Watch accessory we’ve seen hit the market so far, but it might be the first that hopes to solve a potential issue with the upcoming device. You can pre-order your Power Reserve strap now, though it’s probably worth waiting to see how long the actual smartwatch will last per charge before you shell out an extra $250.