My Executive Chef (Kayelle) ordered one of these to make my life easier as Souschef. Unfortunately, it sucks rather than shucks.
Unless the cob is rather small, the work to twist to get the kernels off put me in a sweat. After trying to do four ears, I was red in the face and my hands were shaking. I am not a weakling, but this was hard work.
On the larger ears, I tried attacking from both ends.
The attached photo shows the results, which are worse than if I had used a knife
Do not buy this, but here is the link.