Ceretone, born on Indiegogo, hit the scene last year with impressively tiny hardware that still remains one of the smallest and lightest hearing aids I’ve ever reviewed. At just 0.96 grams each, the Ceretone Core One were so light they threatened to blow away in the wind. With a price of $349 per pair, they had a similarly minimal effect on your bank account. The trouble with the original Ceretone Core One is that they just weren’t very good as hearing aids. They were not tunable, suffered from occasional feedback and interference, and could be controlled only via a rudimentary mobile app. More than a year later, Ceretone has emerged with an update in the form of the Ceretone Core One Pro, and they feel like a full reboot with little in common with the original product. Dated Design Photograph: Chris Null The Core One Pro hearing aids are IP66-rated in-the-ear devices that, like the original Core One, are extremely small and lightweight, though at 1.17 grams per device, they’re noticeably bigger than the originals. They’re also noticeably less attractive. While the original Core One had a white, contemporary design with color-coded eartips, the new Core One Pro features an unfortunately dated, industrial brown body. The included eartips have changed from closed domes to a sort of hybrid open/closed style, and they are now both clear, so you’ll need to look closely to distinguish left and right. (In addition to the preinstalled pair, three additional sets of tips in different sizes are included in the package.) Battery life is now specified at 20 hours per charge, an impressive stat it delivered in my testing, though there is no useful battery meter on the hearing aids or the case. As with the Core One, these hearing aids do not support Bluetooth streaming. Operationally, Ceretone has completely revamped the way these hearing aids work. Namely, you no longer need to use its mobile app to control them, because Ceretone’s mobile app doesn’t work with this model at all. There are only two types of control offered, volume and environmental program mode, and each is controlled via a different method.