JOMOQ Replacement Bands Compitable for Fitbit Alta Ace Activity Tracker, Kids Women Men Soft Sport Breathable Waterproof Wristbands, Quick Release Wristband Accessories Boy Girl (5.0-7.0 inches

It's an excellent replacement for the strap the comes with the Alta - I just wish the attachment points were a little flatter/slimer. I have small wrists and it will take some getting used to. Overall, great product