Please welcome Eyoyo Underwater Fishing Cameras.https://amzn.to/3siEgXn
I have been through 3 sets in 3 years, they can't be sharpened and if they get banged on the ice or any other way even slightly, the pitch will be thrown off and they will just spin. Only negative I have found to the ION.
Brought a pair to machinist and they were sharp but the pitch was off and just spun on the ice. Brought a set to local guy who sharpens all type of blades and he said can't do for the Ion.